Sky-Chaser Web Site (Chris Collura - KG4PJN)

This section is for storm chases done in the central / Midwestern United States during the year of 2007. Since no chase "expedition" (that is where a 2-3 week "block" time was spent chasing at the mercy of whether or not the weather would co-operate) was done this year, all chases in the central USA will be logged in this section. Many chases will be "spot" chases or where only major severe weather "setups" were chased. Here you should find many pictures of lightning, possible tornadoes, along with many severe thunderstorm elements. Keep in mind that this chase log is scientific evidence and portrays my on-going storm chasing research. It has been placed on this page for easy reference and meteorological interests. Please do not plagiarize or copy this document to other sites for distribution.

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STORM CHASING - CENTRAL UNITED STATES - SPECIAL 2007 CHASE LOG

The picture above is a panoramic composite of a beautiful but extremely dangerous HP (high precipitation) supercell thunderstorm near Lipscomb County in the Texas Panhandle on May 23, 2007. Verne Carlson (KB0ZCQ) is standing to the far right taking pictures of the storm as lightning flashes behind him. The reason such a storm looks like this visually is because of the intense rotation in mid-levels odf the storm - This is called a mesocyclone - And these type of storms are responsible for producing tornadoes as well as giant hail and damaging winds. A supercell storm can last for many hours and cause a great deal of severe weather and damage, despite its beautiful appearance.

TABLE OF CONTENTS - CLICK TO GO TO PAGE

ABOUT - ABOUT THIS CHASE LOG

VIDEO - VIDEO SECTION FOR THIS CHASE LOG

MARCH 31 - CHASE LOG FOR MARCH 31, 2007

APRIL 3 - CHASE LOG FOR APRIL 3, 2007

APRIL 11 - CHASE LOG FOR APRIL 11, 2007

APRIL 26 - CHASE LOG FOR APRIL 26, 2007

MAY 1 - CHASE LOG FOR MAY 1, 2007

MAY 15 - CHASE LOG FOR MAY 15, 2007

MAY 23 - CHASE LOG FOR MAY 23, 2007

MAY 26 - CHASE LOG FOR MAY 26, 2007

JUNE 5-10 - CHASE LOG FOR JUNE 5 TO JUNE 10, 2007

END - JUMP TO END OF PAGE

ABOUT THIS CHASE LOG FOR THE MIDWEST

This is a chase log for any chases during 2007 in the Midwest and Central United States that were conducted as "spot" chases during or do not have a dedicated page for them. Each chase section within this area will have its own details and such for that particular chase. This area was set up in the spring of 2007 and is for any chase that was conducted in the US Plains and Midwest. Equipment use in such chases range from cell phone to HAM radio communications, digital / still cameras, video (SD) and high-definition (HD) camcorders, and data logging / GPS via laptop computer. Storm chasing involved driving in harsh conditions and / or for long periods of time.

All chases and observations are in chronological order and a chase number is assigned to each entry. Please bear in mind that all observations adhere to modern storm analysis standards and do not include all storms that occurred in a given area for a particular chase period.

Any kind of storm such as a thunderstorm, tornado, waterspout, tropical cyclone, and extratropical storm can be chased or observed. I have tried to keep this log of any storms that I have observed as accurate as possible, while using terms and expressions to abide by those used by most meteorologists and storm spotters today.

Storm chasing and observation can be extremely dangerous and may result in serious injury or death. I have received intermediate and advanced training for storm spotting in 1996. I strongly urge anyone who is to try their hand at storm spotting to get training before doing so. You must also have a good understanding of meteorology and storm dynamics. "If you don't know what you're doing, Don't do it!" Contact your local National Weather Service office for information on storm spotting and about training to become a Skywarn storm Spotter.

CHOOSE A VIDEO CLIP BELOW - LINKS TO YOUTUBE

May 15, 2007 (Indiana / Ohio) Gustnado Chase Video

May 23, 2007 (KS / OK / TX Panhandle) Supercell Chase Video

June 6, 2007 (South-Central South Dakota) Tornado Video

June 7, 2007 (Wisconsin) Tornadic Supercell / Huge Hail Video

Chase 2007 / 20 Years Music Video (NSCC 2008)

CHASE FOR MARCH 31, 2007

March 31, 2007 was a chase day with severe thunderstorms intercepted in central Iowa near Des Moines near the Interstate 35 corridor. The chase began in the late-afternoon of March 30 leaving Dayton, Ohio and spending the night in Chicago, Illinois. The primary target was central Iowa and that area was targeted early on March 31. Left Chicago and headed toward Interstate 80 and crossed into Iowa by noon. Checked data and found the best possibility of severe weather near Des Moines. A warm front was draped south of the target area, with increasing moisture advection coming in from the south under an upper-level low approaching from the west. The problem with this type of setup was somewhat limited moisture return and, more importantly, having south-southwest winds aloft over southerly surface winds (not much directional shear).

The warm front intersected the cold front / dry punch to the west of the target area, creating somewhat of a "triple point" in west-central Iowa. Temperatures in this area were not very warm, and reached the upper 60's by the afternoon, yielding a surface CAPE of about 1,000 at best. Helicities were also highest in this region, about 150-200, enough for low-topped supercells with the differential vorticity and cold air aloft. Upper winds were strong, with at least 50 Knots of uni-directional bulk shear to 6 km (500 MB) and the exit region of an H3 jet stream moving in farther up ahead of a negative tilt ahead of the upper trough / low. Storm motion was to be very fast and with unidirectional shear, a plan for hail and severe winds were the agenda for chasing. At SPC, a slight was issued for the 16:30z outlook, with a rather high 10% tornado probability, 25% hail, and 30% damaging wind. A mesoscale discussion (MCD) and subsequent tornado watch went up for the same target area.

The trip to the target area continued into Des Moines along I-80. Convection was first encountered about 5-10 miles east of Des Moines. A severe thunderstorm was intercepted in this area, and was part of a multicell line of strong and severe thunderstorms. These storms were intercepted at about 3:30 PM and allowed to move off very quickly to the northeast. Back west, some more storms developed closer to the location of the upper level cold core dry punch. One storm west of Des Moines was highly sheared and briefly LP supercell in nature. The dry punch quickly undercut this region by about 6:30 PM. No tornadoes were observed this day, but some small funnels were noted. The chase finished with a drive pretty much back east on I-80 then into Illinois where the nigh was spent again in Chicago. The drive back to Datyton, Ohio was done the following day. Total mileage was about 792 miles.

MARCH 31 CHASE MAIN PARTICIPANTS

CHASER NAME HOME CITY CALLSIGN CHASE DATES OCCUPATION

CHRIS COLLURA MIRAMAR, FL KG4PJN 3-31 IT CONSULTANT

DETAILED LOG FOR ALL CHASES

1). March 31, 3:30 PM - Penetration of a severe thunderstorm in Polk County, Iowa just north of Interstate 80 and near Altoona along State Road 945. The storm was part of a multi-cell cluster of severe thunderstorms and contained lightning, torrential rains, winds near or exceeding 60-MPH, and hail up to nickel sized. The storms were caused by a low-pressure trough, surface heating, boundary interactions, and a strong upper-level low-pressure area. A 2007 Ford Focus was used to chase the storms. Documentation was still digital photos and HD video. A tornado watch was also valid for this area until 7 PM EDT.

2). March 31, 6:00 PM - Observation of a small but severe thunderstorm in Dallas County, Iowa just east of Waukee, Iowa along Highway 6. The storm was a small LP type "mini" supercell storm in a highly-sheared environment. The storm produced occasional lightning, and reports of 3/4" hail came with this storm. The hail was not intercepted. The storm produced a lowering and small funnels during its mature stage. The storms were caused by a low-pressure trough, surface heating, boundary interactions, and a strong upper-level low-pressure area. A 2007 Ford Focus was used to chase the storms. Documentation was still digital photos and HD video. A tornado watch was also valid for this area until 7 PM EDT.

This concludes the chase log for the Central Iowa chase trip on March 31, 2007. The summary includes a total of 2 severe thunderstorms. The main chase vehicle conducting all chases was a 2007 Ford Focus. This information was prepared exclusively for the National Weather service and the team of Skywarn storm spotters.

GALLERY FOR MARCH 31, 2007

	Storms begin to develop as viewed from 40 miles or so east of Des Moines, Iowa. The storms here are developing but forming a line of storms and not supercellular.
	Some of the first thunderstorm cells to go up were low-topped (under 30,000 feet high) in nature. This is due to low surface temperatures (in the 60's F). In this picture, a low topped thunderstorm erupts about 50 miles east of Des Moines, Iowa.
	A small but interesting storm cell develops about 45 miles east of Des Moines, Iowa. Note the updrafting scud and small wall cloud associated with this small cell in a highly-sheared environment.
	Here is a view of the base and precipitation (rain and hail) of a severe thunderstorm approaching Altoona, Iowa just south of Interstate 80 in Polk County, Iowa. This storm was part of multi-cell line of strong and severe storms pushing through the area.
	This is a picture of the updraft region of a small "mini" LP supercell storm just west of Des Moines near Waukee, Iowa. An interesting lowering / Wall cloud can be notes with this storm, which also produced nickel-sized hail. The view is to the south and southwest.
	Here is a picture of the updraft region of the same "mini" LP supercell storm, developing in a highly-sheared environment, just west of Des Moines, Iowa. The storm is moving rapidly to the north and northeast. Note the small hail core to the lower left (grey streak). The view is to the east.
	East of the small and weak supercell storm, an RFD-like feature (clear slot) can be seen. The view is to the southwest of Des Moines, Iowa.
	The upper-level low-pressure system not only produces severe thunderstorms, but this incredible display of mammatus-like clouds. The DVA, or differential vorticity advection (upper level low) moving overhead causes this interesting "swirling" mass of clouds high over east-central Iowa. These clouds are an aviation hazard because they present severe turbulence to aircraft.
	The chase ends with this spectacular double rainbow as the sun sets. This is approaching the eastern Iowa / western Illinois border on Interstate 80 looking east and northeast.

CHASE FOR APRIL 3, 2007

April 3, 2007 was another moderate-risk chase day with severe thunderstorms intercepted in central and southern Indiana from just east of Indianapolis and points southward to near Louisville, Kentucky. The chase began with forecasting and leaving Dayton, Ohio at about 2:15 PM and headed west along Interstate 70 into Indiana towards Indianapolis. A cluster of very severe thunderstorms was on-going with two major line segments pushing through central Indiana by early afternoon. An intense "tail-end charley" type storm, HP in nature but outflow dominant, was noted on the southern ends of the two line segments, one near Indianapolis and the other about 100 miles to the southwest. Meanwhile, forecasting revealed a developing low-pressure system over Iowa and Illinois with an attendant upper level system (500 MB differential vorticity aloft). The storm prediction center posted a 10% tornado probability along with a 45% hatched hail and 45% damaging wind threat (moderate risk) over the southern part of Indiana.

A tornado watch was issued for parts of southwestern Indiana and a severe thunderstorm watch for east-central and southeastern Indiana valid until 10 PM EDT. Traveling west on Interstate 70, the line of storms was encountered near Greenfield, Indiana and the chase turned south on Highway 9 towards Shelbyville. A severe thunderstorm was encountered north of Shelbyville, Indiana by 4 PM with a well-developed gust front and a small funnel was noted on the storms forward flank. Continuing south on Highway 9, then to Highway 31 through light to moderate rain, a few accidents were observed, one near the intersection of Highway 7 and Highway 9 which was called to 911 emergency. Wind damage to a farmstead was also observed near this location. The chase continued south along Highway 31 and onto Interstate 65. The southern end of the second line segment was reached about 10-15 miles north of Clarksville, Indiana and was also tornado-warned (radar indicated). This storm produced hail and high winds. A fuel stop was attemped in Clarksville but the storms disrupted power forcing the chase south to Louisville, Kentucky then east on Interstate 71 (with a fuel stop on the east side of town) and back toward Cincinnati, Ohio.

The trip ended when the storms became completely linear. Headed northest on Interstate 71 to Interstate 75, stopping for dinner south of Cincinnati, then continued north back towards Dayton, Ohio. Total mileage was 364.8 miles.

APRIL 3 CHASE MAIN PARTICIPANTS

CHASER NAME HOME CITY CALLSIGN CHASE DATES OCCUPATION

CHRIS COLLURA MIRAMAR, FL KG4PJN 4-3 IT CONSULTANT

DETAILED LOG FOR ALL CHASES

1). April 3, 3:30 PM - Penetration of a severe thunderstorm in Shelby County, Indiana just north of Shelbyville along Highway 9. The storm was at the southern end of a multi-cell cluster / line segment of severe thunderstorms and contained lightning, torrential rains, winds near or exceeding 60-MPH, and small hail. This storm had a spectacular shelf cloud associated with its gust front. Some small funnels were noted on the storms forward flank. Wind damage occured near this storm with power outages, tree damage, and parts of a small out building destroyed. This storm had some HP supercell characteristics but was outflow dominant. The storms were caused by a low-pressure trough, surface heating, approaching strong cold front, and a strong upper-level low-pressure area. A 2007 Ford Focus was used to chase the storms. Documentation was still digital photos and HD video. A severe thunderstorm watch was also valid for this area until 10 PM EDT.

2). April 3, 6:00 PM - Penetration of a very severe thunderstorm in Clark County, Indiana along Interstate 65 and north of Clarksville. The storm was at the southern end of a second multi-cell cluster / line segment of severe thunderstorms farther south than the other segment earlier east of Indianapolis. This storm contained frequent lightning with some close hits, extremely torrential rains, winds gusting over 65-MPH, and nickel-sized (3/4") hail. The main hail core of this storm had hail to 1 3/4" but was not intercepted. This storm had a weak rotating region and prompted a tornado warning for the county to the northeast as well. Power outages and tree damage was also noted with this storm. The storm also caused traffic accidents. This storm had some HP supercell characteristics but quickly became under-cut and outflow dominant. The storms were caused by a low-pressure trough, surface heating, approaching strong cold front, and a strong upper-level low-pressure area. A 2007 Ford Focus was used to chase the storms. Documentation was still digital photos and HD video. A severe thunderstorm watch was also valid for this area until 10 PM EDT.

This concludes the chase log for the Central and Southern Indiana chase trip on April 3, 2007. The summary includes a total of 2 severe thunderstorms. The main chase vehicle conducting all chases was a 2007 Ford Focus. This information was prepared exclusively for the National Weather service and the team of Skywarn storm spotters.

GALLERY FOR APRIL 3, 2007

	Here is a view of the mammatus associated with the blowoff east of the cluster / line-segment of severe thunderstorms when looking west along Interstate 70 about 50 miles east of Indianapolis, Indiana. The actual storm cells are on the horizon in the lower-left portion of the picture.
	The southern storm of the line of thunderstorms southeast of Indianapolis produces outflow and this large shelf cloud near Shelbyville, Indiana. The view is to the south and southwest.
	Here is a picture just under the shelf cloud of the severe thunderstorm near Shelbyville, Indiana. The view is to the south. There is also an area of weak rotation (forward flank mesocyclone) forming on the southern end of the shelf cloud in the center of the picture.
	This is a closer view of the weak forward-flank low-level mesocyclone on the southeastern side of the severe thunderstorm near Shelbyville, Indiana. The view is to the south and southeast.
	A small funnel cloud develops within the churning mass of clouds associated with the shear-axis of the gust front where southerly winds meet colder stiff northwesterly outflow winds.
	Wind damage observed near Highway 31 and Highway 7 in Bartholomew County, Indiana after the storm line passes. This is a portion of a sheet metal roof blown off a farm stand. This was also across the street from a major car accident at the intersection of Highway 31 and Highway 7. Both were reported to 911 emergency.
	Darkness falls early at 6 PM EDT beneath the base of a severe and tornado-warned storm north of Clarksville, Indiana. This storm contained hail up to half-dollar sized, and was racing eastward at over 50-MPH.

CHASE FOR APRIL 11, 2007

April 11, 2007 was pretty much a short "impromptu" chase along Interstate 70 from Southwestern Ohio into East-Central Indiana to intercept a line of strong and severe thunderstorms. The chase began leaving Dayton, Ohio at about 6 PM and heading west into Indiana along Interstate 70 after looking at radar and seeing a developing line of severe thunderstorms moving across Indiana near Indianapolis. An area of light to moderate rain and cool temperatures, ahead of a warm front, moved off to the northeast and a clear slot allowed limited heating in a region with very cold air aloft.

A severe thunderstorm watch was issued for parts of east-central Indiana and parts of southwestern Ohio. These were actually two watch areas, watch 126 valid until 11 PM EDT and another watch 127 farther east valid until 1 AM EDT. The SPC outlook called for a slight risk centered over east-central Indiana with a 5% tornado, 15% damaging wind, and 15% hail possibility. A severe thunderstorm was encountered in Wayne County, Indiana at about 7 PM along Interstate 70. The storm had winds strong enough to blow over a semi-trailer headed westbound. The storms moved rapidly northeast and could not be intercepted more than once. A tornado warned storm also was present in Madison County, about 15 miles to the northwest of the severe storm intercepted. The storm producing the tornado was not observed. After the quick intercept, a fuel stop was done and the chase finished by heading back east into Dayton, Ohio. Total mileage was about 120 miles.

APRIL 11 CHASE MAIN PARTICIPANTS

CHASER NAME HOME CITY CALLSIGN CHASE DATES OCCUPATION

CHRIS COLLURA MIRAMAR, FL KG4PJN 4-11 IT CONSULTANT

DETAILED LOG FOR ALL CHASES

1). April 11, 7:00 PM - Penetration of a severe thunderstorm in Wayne County, Indiana along Interstate 70. The storm was a bow-echo type structure in a multi-cell line of strong and severe thunderstorms. Lightning, torrential rains, winds near or exceeding 60-MPH, and small hail were observed with this storm. This storm also produced an impressive shelf cloud associated with its gust front. The strong outflow winds of the storm also overturned a semi trailer headed westbound on Interstate 70 in Wayne County. The storms were caused by a low-pressure trough, approaching strong cold front and strong surface low, and a strong upper-level low-pressure area (differential PVA and very cold air aloft). A 2007 Ford Focus was used to chase the storms. Documentation was still digital photos and HD video. A severe thunderstorm watch was also valid for this area until 11 PM EDT.

This concludes the short chase log for East-Central Indiana chase trip on April 11, 2007. The summary includes a total of 1 severe thunderstorm. The main chase vehicle conducting all chases was a 2007 Ford Focus. This information was prepared exclusively for the National Weather service and the team of Skywarn storm spotters.

GALLERY FOR APRIL 11, 2007

	This is the start of this very small local chase. Looking west and heading across the border from Ohio into Indiana along I-70, the distinct cirrus anvil blowoff marks the leading edge of the line of thunderstorms. The sun is heating the ground, through a break in precipitation (called a dry slot) behind a large shield of rain that lasted all day, allowing heating to take place and storms to become strong and severe. The storms are developing along a region of convergence under a region of very cold air aloft.
	Still headed west, and ahead of the line of thunderstorms, a turbulent layer of cumulus known as "agitated cumulus" develops. This is an indication that the atmosphere is rapidly becoming unstable.
	This is a view of the shelf cloud and gust front associated with the intense portion of the bow-segment of the severe thunderstorm line. The view is to the west along Interstate 70 in Wayne County, Indiana. This storm produced hail and winds over 60 MPH, and blew over a tracter trailer in the same county. Note the interesting updraft region to the lower right side of the picture and hail shaft just to its left (center and to the left).

CHASE FOR APRIL 26, 2007

April 26, 2007 was another "back-yard" local chase that started heading west along Interstate 70 from Southwestern Ohio into Eastern Indiana to intercept an area of strong and severe thunderstorms. The chase began leaving Dayton, Ohio at about 3:30 PM and heading west into Indiana along Interstate 70 after looking at radar and seeing developing strong and severe thunderstorms moving across Indiana. The activity was developing ahead of a strong upper-level low and in the warm sector between the warm front and cold front farther west. Limited surface heating also took place in this region with very cold air aloft and moderate vertical wind shear.

A tornado watch was issued for parts of eastern Indiana and parts of western Ohio. There were actually several watch areas, inwhich watch 191 was valid until 10 PM EDT in the area where the chasing was done. The SPC outlook called for a slight risk centered over eastern Indiana and western Ohio with a 5% tornado, 30% hail, and 15% damaging wind possibility. After checking data on the best area (as there were many storms developing in this area), and heading south along Highway 26, a severe thunderstorm was encountered in Union County, Indiana at about 6 PM near the town of Liberty. The storm developed ahead of the line of strong thunderstorms and actually became a supercell storm for a short while. After intercepting this storm, the chase finished by heading back east along Highway 35 into Dayton, Ohio then north on 75 as another area of strong storms weakened and headed east. Total mileage was about 150 miles.

APRIL 26 CHASE MAIN PARTICIPANTS

CHASER NAME HOME CITY CALLSIGN CHASE DATES OCCUPATION

CHRIS COLLURA MIRAMAR, FL KG4PJN 4-26 IT CONSULTANT

DETAILED LOG FOR ALL CHASES

1). April 26, 6:00 PM - Observation of a strong to severe thunderstorm in Union County, Indiana near Highway 27 and Route 44 and west of Liberty Indiana. The storm was a small HP supercell type of storm developing ahead of a squall line of strong and severe thunderstorms. As the line caught up with this short-lived supercell, it evolved into a bow segment and merged with the line of thunderstorms. Frequent lightning with some close hits, torrential rains, winds near 50-MPH, and small hail were observed with this storm. This storm also produced the "stacked-plates" appearance while in supercell mode. A small wall cloud / lowering was also noted at the time of RFD occlusion but did not last long. The storms were caused by a low-pressure trough, approaching surface low, and a strong upper-level low-pressure area (differential PVA / cold air aloft) to the west. A 2007 Ford Focus was used to chase the storms. Documentation was still digital photos and HD video. A tornado watch was also valid for this area until 10 PM EDT.

This concludes the short chase log for Eastern Indiana and Southwestern Ohio chase trip on April 26, 2007. The summary includes a total of 1 severe thunderstorm. The main chase vehicle conducting all chases was a 2007 Ford Focus. This information was prepared exclusively for the National Weather service and the team of Skywarn storm spotters.

GALLERY FOR APRIL 26, 2007

	A small HP supercell storm develops ahead of a line of strong and severe storms in Union County, Indiana near the town of Liberty. The view here is southwest. Note the highly sheared nature of the storm updraft.
	Here is another picture of the same small HP supercell storm in Union County, Indiana. In this view here is southwest, you can just make-out the striations on the north and northeast side of the storm updraft.
	Here is a view of the line of strong and severe thunderstorms pushing from eastern Indiana into western Ohio. The view is to the north.
	The supercell shown earlier became involved with the line of strong and severe storms, although weakening, an interesting "clear-slot" (RFD?) develops in that same area. The view here is to the northeast.
	View of the shelf cloud associated with the gust front from the line of strong and severe thunderstorms. The view is to the southwest and the cold outflow is pushing in from right to left.

CHASE FOR MAY 1, 2007

May 1, 2007 was a storm chase which started by heading north on Interstate 75 out of Dayton, Ohio at about 2:30 PM for the original target area near and southeast of Toledo, OH. Forecasting earlier that day revealed a warm-frontal boundary draped across northern Ohio with a developing surface low near Chicago, IL. Surface winds south of this boundary were WSW with temperatures in the low 80's (with a dewpoint near 60) and easterly winds and temperatures in the 60's north of it. Upper winds at 500 and 300 MB were WNW at up to 50 and 80 knots, respectively. Lapse rates were also steep (6 - 7 deg C) in this area as well, so the main mode expected would be large hail with any tornado possibilities early during initiation before evolution to multicell severe mode. According to SPC, the outlooks issued were nearly identical on both the 16:30z and 20:00z outlooks, with a 5% tornado, 30% hail, and 30% damaging wind probability. A mesoscale discussion (MCD 0636) went out for the area and a severe thunderstorm watch (205) was issued for northern Ohio valid until 8 PM EDT.

The chase continued north with a data-stop in Lima, OH where an isolated developing supercell storm was noted just south of Toledo, OH. Rushing north and northeastward on Interstate 75, this supercell was noted visually and approached from the southwest. Headed east on Highway 6 into Wood County, the updraft portion of this severe (and radar-indicated tornado) warned storm was noted near Fremont, and a large RFD clear-slot was noted. The storm core was not penetrated and no tornadoes were observed with this storm. It eventually moved north of the boundary, became elevated, and weakened. More storms began developing to the south, and another severe storm developed in this area by about 6 PM. Heading east and then southeast on Highway 20 through Sandusky County, then south on Highway 250 / State-Road N (detour for 250) out of Norwolk, this severe storm was encountered and large hail covering the ground was observed northeast of North Fairfield and Highway 162. These storms moved east very quickly, and the one near North Fairfield had some interesting features / lowerings on its updraft. Hail up to 1" was observed with this storm before it moved rapidly east and weakened.

Heading east on Highway 162 through northern Ashland County, another small supercell-type storm developed to the northeast of Ashland, OH by about 7 PM. The core of this small storm was not penetrated, but its updraft and hail-shafts were noted. This storm became severe-warned, but weakened shortly after. Heading south on 301 near Spencer, then towards Interstate 71, one final severe storm was encountered near West Salem, and flash flooding started to occur in the area by about 8 PM. SPC also issued another Mesoscale discussion (MCD 0637) and severe thunderstorm watch 206 valid until 11 PM EST for a bit farther east than expired watch 205. By this time most storms were line-segments and clusters, so the chase was wrapped up at dark by heading back SW along Interstate 71, then to Interstates 270 and 70 near Columbus, then returning to Dayton off Interstate 75 by about 10 PM. The total mileage for this chase was just under 413 miles.

MAY 1 CHASE MAIN PARTICIPANTS

CHASER NAME HOME CITY CALLSIGN CHASE DATES OCCUPATION

CHRIS COLLURA MIRAMAR, FL KG4PJN 5-1 IT CONSULTANT

DETAILED LOG FOR ALL CHASES

1). May 1, 4:30 PM - Observation of a severe thunderstorm near Wood County, Ohio near Highway 6 30 miles southeast of Toledo and west of Fremont. This storm was a supercell storm, and an RFD (rear-flank downdraft) was noted on the updraft (southwestern side) of the storm. The core of this storm was not penetrated, but contained hail to nickel sized (3/4"). A small wall cloud / lowering was also noted just north of RFD clear-slot but did not last long. The storms were caused by a low-pressure trough, approaching surface low, surface boundary / warm front, surface heating, and an upper trough (NW flow and cold air aloft). A 2007 Ford Focus was used to chase the storms. Documentation was still digital photos and HD video. A severe thunderstorm watch was also valid for this area until 8 PM EDT.

2). May 1, 6:30 PM - Observation and penetration of a very severe thunderstorm near Highway 162 along Old State Road N to the northeast of North Fairfield, Ohio. The storm was a small supercell-like storm on the western end of a cluster of strong and severe storms. When penetrating the storm, large hail (up to 1") was observed covering the ground, along with lightning, heavy rains, and winds over 50-MPH. Some tree damage was noted with this storm. The updraft side of this storm also had some interesting lowerings / funnels, but no tornadoes touched down. The storms were caused by a low-pressure trough, approaching surface low, surface boundary / warm front, surface heating, and an upper trough (NW flow and cold air aloft). A 2007 Ford Focus was used to chase the storms. Documentation was still digital photos and HD video. A severe thunderstorm watch was also valid for this area until 8 PM EDT.

3). May 1, 7:30 PM - Observation of a severe thunderstorm northeast of Ashland, Ohio in Ashland County from north of that area by about 10-15 miles. The storm was a mini supercell for some time before weakening. The core of this storm was not penetrated (but contained hail to 1"). The storm updraft contained weak rotation, giving the updraft a striated appearance (barber-pole). The storms were caused by a low-pressure trough, approaching surface low, surface boundary / warm front, surface heating, and an upper trough (NW flow and cold air aloft). A 2007 Ford Focus was used to chase the storms. Documentation was still digital photos and HD video. A severe thunderstorm watch was also valid for this area until 8 PM EDT.

4). May 1, 8:30 PM - Observation of another severe thunderstorm south of Ashland, Ohio in Ashland County near Interstate 71. The storm was highly outflow-dominant but had some HP supercell characteristics. The core of this storm passed with small hail, frequent lightning, torrential rains, and winds near 60-MPH. The largest impact of this storm that it produced large amounts of rain in a short period of time, and caused flash flooding. The storms were caused by a low-pressure trough, approaching surface low, surface boundary / warm front, surface heating, and an upper trough (NW flow and cold air aloft). A 2007 Ford Focus was used to chase the storms. Documentation was still digital photos and HD video. A severe thunderstorm watch was also valid for this area until 11 PM EDT.

This concludes the short chase log for Eastern Indiana and Southwestern Ohio chase trip on May 1, 2007. The summary includes a total of 4 severe thunderstorms. The main chase vehicle conducting all chases was a 2007 Ford Focus. This information was prepared exclusively for the National Weather service and the team of Skywarn storm spotters.

GALLERY FOR MAY 1, 2007

	A supercell storm (S of Toledo, OH) looms over the horizon looking northward on I-75 and just north of Lima, OH. The storm here is about 30 miles away, and has an impressive pileus "cap" cloud on its overshooting top. The storm was both severe and tornado warned (radar-indicated) at the time this picture was taken.
	A large clear slot is noted on the southern and soutwestern side of the supercell storm, now about 30 miles SE of Toledo in Wood County, OH. This clear area in the center of the picture is caused by sinking air known as a rear-flank downdraft, or RFD. The rotating portion (in the mid levels) of the supercell storm is to the lower right in this picture.
	This is a picture of a hail shaft (and hail "foot") from a severe thunderstorm near North Fairfield, OH. If you look closely to the lower left, some "hail fog" can also be seen.
	Large hail, anywhere from nickel to quarter sized (3/4" to 1") covers the roadway (Highway 162) to the northeast of North Fairfield, OH.
	As hail covers the ground and suddenly melts, an interesting fog forms close to the ground because of the cooling effects of the hail. This is called a HAIL FOG.
	This is a picture of the updraft region of the storm east of North Fairfield, OH.
	This interesting "feature" caught my eye under the updraft of the storm near North Fairfield, OH. I cannot confirm if this was roating or not, as it can either be a gustnado or scud. Maybe a "sheriffnado"?
	Another severe storm goes up in Ashland County near and northeast of Ashland, OH. The stout and rock-hard updraft of this developing small supercell can be seen in this picture through a break in the lower clouds.
	Here is a full picture of the lower portion of the small supercell storm that is developing near Ashland, OH. Note the small RFD slot developing near the center of the picture (and slightly right). The view is due south.
	This "feature" developed near the weak RFD clear-slot on the small supercell storm near Ashland, OH. I am not sure what this is (near center of picture), but it looks like a narrow hail shaft.
	This is a picture, also in Ashland County, of some flash flooding (foreground) that started due to the high rainfall rates of the storms. A severe storm, HP supercell in nature, can be seen in the background with a large shelf cloud ahead of its weak but wet RFD.
	Flash flooding also causes dry creek / stream beds to rise forming small torrents of muddy water. This rushing creek is covering a tree trunk.
	Here is another picture of flash flooding occurring across a roadway in Ashland County. The water here is only several inches deep.
	As more storms develop and move over the same area, flash flooding gets worse. This small roadway is nearly impassible due to swift running water across it.
	A small shear-funnel type lowering occurs along the shelf cloud of a severe storm moving across Ashland County.
	While filming hail and torrential rains and strong winds across Interstate 71 in Ashland County, lightning strikes a tree across the highway about 100 yards away. Unfortunately, the bolt itself is out of frame to the right, but the bright light from it illustrates the intensity of the strike! Note the hail stones in the highway as well.
	Here is another CG (cloud to ground) lightning bolt over Interstate 71. This one is much father away then the last picture!
	Two more CG lightning bolts poke the ground in southwestern Ashland County north of Interstate 71.
	Here is another CG lightning bolt striking the ground north of Interstate 71 in Ashland County, OH. These storms produced a lot of lightning once evolution to multicell (cluster) / linear (squall line) mode occurred near the evening.

CHASE FOR MAY 15, 2007

May 15, 2007 was a storm chase with an original target of northeastern Indiana. This chase started at about 2:30 by heading north on Interstate 75 out of Dayton, Ohio and then west on Interstate 70 to Richmond, Indiana to check data. There were two areas to watch. First, a cold front and intense prefrontal squall line was pushing in from the west and currently in western Indiana / eastern Illinois at the time. Second, a region of convergence over northern Indiana accompanied by a weakening cap, a moisture / instability axis, and a weak surface low SE of Chicago, IL. The target area was set at Fort Wayne, Indiana which could be reached via Highway 27 north out of Richmond. Storms began developing along this region of convergence by about 4 PM EDT. Wind fields were SW from the surface to about 500 MB and increased from about 20 Knots to 40 Knots in that region. Winds veered a bit to 60-70 Knots at 300 MB and were WNW south of a jet maximum over the US Great Lakes. According to SPC, the 16:30z outlook called for a 2% tornado, 30% hail, and 30% damaging wind probability. By 20:00z, the outlook had the tornado probability upgraded to 5% for northern Indiana, southern Michigan, and NW Ohio. A mesoscale discussion (MCD 0809) went out for parts of northern Indiana, NW Ohio, and southern Michigan and severe thunderstorm watch #275 was issued shortly after valid until 10 PM EDT.

Arriving at Fort Wayne, the convergence line was encountered just north of town after dealing with rush-hour traffic at roughly 5:30 PM. Some multicell clusters of strong thunderstorms developed with this feature, but were high based and weakened. Meanwhile, a developing and very strong squall line containing damaging winds was pushing through Kosciusko County to the NW of Fort Wayne and Columbia City / Peru. This prompted a chase down Interstate 69 to the SW, then west on Highway 14 to get out of Allen County. In rural areas near Dunfee in eastern Whitley County, the gust front and intense squall line was encountered at about 6:15 PM EDT. Strong winds to 75 MPH and gustnadoes were observed in this area. The line was moving east at more than 40 MPH, and an attempt to back-track along Highway 30, then back NE and N on Interstate 69 failed to catch up with an intense cell in this line near Auburn.

The end of the chase in northern Indiana started by heading back east and southeast into Ohio on Highway 8 into Hicksville, then east on highway 18 to Defiance. Frequent lightning was observed on the backside of the line segments in this area at about 7:30 PM. The track continued to Napoleon on Highway 24, then east on Highway 6 to Interstate 75 for a fuel-stop, then south back into Dayton by 10:30 PM.

Another round of severe thunderstorms developed in Ohio near Miami and Montgomery Counties north of Dayton at about 11 PM EDT, and MCD 815 was issued for this area (then severe thunderstorm watch 276 valid until 3 AM). Once severe cell in this storm cluster acquired rotation and was tornado-warned. This storm was followed into Springfield, OH along Interstate 70 where a large wall cloud was observed. This storm also produced hail and winds over 60 MPH. The chase officially ended at 11:45 PM EDT by heading back into Dayton, Ohio. The total mileage for this chase was about 450 miles total.

MAY 15 CHASE MAIN PARTICIPANTS

CHASER NAME HOME CITY CALLSIGN CHASE DATES OCCUPATION

CHRIS COLLURA MIRAMAR, FL KG4PJN 5-15 IT CONSULTANT

DETAILED LOG FOR ALL CHASES

1). May 15, 6:15 PM - Penetration of a very severe thunderstorm in eastern portions of Whitley County, Indiana on a rural farm road near Dunfee between Highways 30 and 14. This storm was a multicell squall line of severe thunderstorms. This storm had most of its destructive winds well ahead of its precipitation region and was a bow-segment in the line of thunderstorms. At least two major gustnadoes were observed crossing fields in Whitley County. One large gustnado was filled with debris (corn stalks and leaves) and another nearly reached cloud-level. Winds estimated from 70-75 MPH with airborne debris and dust was observed. The storm north of the bow-segment had weak rotation, and a small RFD-like clear slot was noted on its southern side (rotating "head" storm). Only light rain was encountered with this storm, and occasional lightning. The storm also had a history of producing wind damage. Many trees and power lines were observed damaged by the storm. The storm was caused by a prefrontal wave (squall line) ahead of a strong cold front, surface low / trough, surface heating, and an upper-level disturbance. A 2007 Ford Focus was used to chase the storms. Documentation was still digital photos and a camcorder. A severe thunderstorm watch was also valid for this area until 10 PM EDT.

2). May 15, 11:00 PM - Penetration of another severe thunderstorm on the western side of Springfield, Ohio north of Interstate 78 and along Highway 68 in Clark County, Ohio. This storm was an HP supercell storm embedded in a cluster of strong and severe thunderstorms. A tornado warning (radar-indicated) was issued for this storm. A large wall cloud was observed, illuminated by nearly continuous lightning, north of Interstate 70 and near Medway. Funnels or tornadoes, if any, were not observed. The core of the storm passed and produced torrential rains, 60-MPH winds, frequent lightning, and hail up to dime-sized (1/2"). Some tree damage and power outages were also noted in the path of this storm, which also had a wind-damage history. The storms were developing ahead of a strong cold front, and were supported by a surface trough / low and an upper level disturbance. A 2007 Ford Focus was used to chase the storms. Documentation was HD video. A severe thunderstorm watch was also valid for this area until 3 AM EDT.

This concludes the chase log for Northern Indiana and Ohio chases on May 15, 2007. The summary includes a total of 2 severe thunderstorms and at least two large gustnadoes. The main chase vehicle conducting all chases was a 2007 Ford Focus. This information was prepared exclusively for the National Weather service and the team of Skywarn storm spotters.

GALLERY FOR MAY 15, 2007

	Here is a picture of the shelf cloud associated with the gust front of a very intense squall line moving through eastern rural sections of Whitley County, Indiana near Arcola south of Highway 30. This is a portion of the squall line called a "bow echo" because it appears as a "bow" on radar. Very strong winds are associated with this type of thunderstorm line. The view is to the west.
	A strong gustnado crosses a rural farm road in Whitley County, Indiana and is filled with rapidly rotating debris (dust, leaves, and corn-stalks)!
	Here is another larger gustnado about 500 yards away to my north with dust nearly reaching cloud level. I am also getting battered by 70 to 75-MPH winds from the west, along with flying corn-stalks, dust, dirt, rocks, etc.
	This is a view of the thunderstorm cell north of the "bow-segment" of the squall line moving through Indiana north of Fort Wayne. This cell has rotation, maked by an RFD-like clear slot in the cloud base (brighter region cutting in from left to right). The view is to the north.
	Here is a view, looking northeast in Montgomery County, OH (north of Dayton) at the rear-flank of a tornado-warned (radar indicated) severe storm. Interesting lowerings / wall cloud features are illuminated by lightning. This storm was at about 11:00 PM at night and was a rotating storm embedded in a cluster of strong and severe thunderstorms.
	Here is another view of the tornado-warned storm moving from northern Montgomery County into Clark County, Ohio. Wall cloud is unmistakable to the left as lightning illuminates the (vault?) and / or precipitation core. The view is to the NNE.
	This is another picture of the severe thunderstorm and (radar indicated) tornado-warned storm. The wall cloud (view is to the NE) is entirely illuminated by frequent lightning (it's 11:30 PM EDT). Note the possible RFD clear slot to the left, and a very interesting lowering to the lower-left. The storm here is in Clark County, Ohio and is west of Springfield and north of Interstate 70.
	The storm core passes through the western portions of Springfield, OH and produces 60-MPH winds and hail from pea to dime sized.

CHASE FOR MAY 23, 2007

May 23, 2007 was an involved chase requiring a special trip to SW Kansas and the Texas / Oklahoma panhandles. This was what is referred to as a "spot" chase where "major" severe weather setups are targeted. Analysis and forecasting began on Tuesday, May 22 with a persistent ridge in the central and western US giving way to a trough pattern. Models and forecasting revealed a good chance of severe thunderstorms on both May 22 and May 23 (especially May 23) anywhere from central Kansas southwestward to the Texas Panhandle (north of Amarillo). The day of May 23 was decided to be of great interest, and the Storm Prediction Center already had a moderate-risk outlook (with a 45% hatched area) in this same region. The chase began by taking a last minute flight from Dayton, Ohio to Kansas City, Missouri (with a Milwaukee Wisconsin connection) late evening (8:55 PM EDT) on May 22. This flight arrived in Kansas City at 11:25 PM CDT on May 22 and arrangements for car-rental were also made once there. Anticipating a primary target of Dodge City, Kansas, I decided to head west along Interstate 70 and spend the night in Abilene, Kansas (arrived there at about 1:30 AM on May 23 and checked into a motel for the night).

During the morning on May 23, I set the rental vehicle up with HAM radio equipment, GPS / Laptop, and camera equipment, and forecasted for the setup unfolding that day. A cold front pushed into northern Texas and the Oklahoma panhandle a bit more than previously anticipated. A developing surface low pressure was underway in northeastern New Mexico. Meanwhile, analysis and model runs showed an increasing set of wind fields aloft, with good directional shear (SE at surface, SSW at 850 MB, veering to W at 300 MB diffluent jet exit region). This was also ahead of a shortwave (500 MB) trough. CAPE was to be near 3,000 J and helicities running from 200 to 300. The target area was adjusted to near Buffalo, Oklahoma in Harper County. This was about 100 miles farther south than the original target of Dodge City, Kansas. Another chase companion, Verne Carlson, also was en-route to this area with his son Michael Carlson.

Packed up and left the motel in Abilene, Kansas by about 9:30 AM on May 23. Headed west on I-70 to Highway 15 south to meet up with Highway 56. Headed west on Highway 56 to Great Bend then south on Highway 183 (past devastated Greensburg, Kansas) towards Highway 160, then west through Protection, Kansas to pick up Highway 283 southbound towards Oklahoma and into Buffalo. There were many problems with construction traffic southbound on Highway 283, so a detour was sought via Highway 1 (by back-tracking along Highway 160), then finally west on Highway 64 in Oklahoma to Buffalo. Met up with Verne and his son near Laverne, OK just as a supercell storm was initiating in that area south of the intersection of Highway 270 and Highway 283 in Harper County!

This first supercell storm rapidly formed south of the quasi-stationary front and quickly intensified. This storm was followed during its lifespan along Highway 270, then northward along Highway 46. The storm had a large rotating wall cloud and produced a brief tornado before occlusion on Highway 46. Golf ball (1.75") to hens-egg (2") was found laying on the ground with this storm. The supercell storm eventually got north of the stationary / warm front, became elevated, and weakened. Attention turned to other severe storms developing farther to the southwest. The chase then turned southward along Highway 283 through the town of Shattuck, Oklahoma to Highway 60, which runs into Texas. This was targeting the "tail-end Charley" supercell that was developing on the south end of a line of smaller supercell thunderstorms. Highway 213 was picked up out of Higgens, Texas which led to Highway 305 near Lipscomb. This is where the "tail-end Charley" storm was encountered, which by the time it was reached, was a large HP supercell thunderstorm.

The supercell storm near Lipscomb lasted several hours and had a striking visual appearance of "stacked-plates". This storm also produced several lowerings (or wall clouds) that might even have been brief tornadoes (in some cases wall cloud was to the ground)! A large "chaser convergence" took place near this supercell as well. This storm also produced frequent lightning with many close hits, large hail (golf ball size was observed), torrential rains, and winds gusting 75-80 MPH. This supercell was abandoned as darkness fell at around 9 PM and it was time to begin working my way back into Kansas. The chase ended with a track northward near Darrouzett, Texas along FM 2248 off Highway 305 and Highway 15 where very strong winds and large hail was encountered on the north side of the supercell (mesocyclone). These conditions let up back near 270, where the track went west then north on Highway 23 with a fuel-stop in Beaver, Oklahoma. The storm evolved into a large MCS of strong and severe thunderstorms afterwards.

By 9 PM, the chase was finished, and Verne / Michael Carlson began their track back to Denver, Colorado as I prepared for my long trip back to Kansas City, Missouri. Both these were drive times of 7-8 hours, so May 23 to May 24 was to be a planned night of no sleep. I continued out of Beaver headed east on Highway 64 back to Buffalo, then northward on Highway 183 (283 was to be avoided because sections of it were closed near the OK / KS border). Another small severe storm was encountered along the Highway 64 route. Heading north on Highway 183, then jogging east on Highway 54 to pick-up 183 again near Greensburg, Kansas (or actually, what's left of it), I pretty much stayed with Highway 183 until Hays, Kansas to pick up Interstate 70 east for the long haul back to Kansas City, Missouri (240 miles east of Hays). The large MCS of strong thunderstorms kept down progress (both before and during the drive on I-70) and Kansas City was not reached until 5 AM!

The flight back to Dayton was 5:50 AM CDT ... For some God-forsaken miracle, I managed to reach Kansas City airport (in Missouri) via the Interstate 435 / 29 interchange, which is about 20 miles north of Interstate-70, by 5:20 AM, return the rental vehicle and reach the terminal by 5:35 AM, check-in and through security by 5:45 AM, and depart on-time at 5:50 AM CDT ... Don't ask me how I did this ... But I was back in Dayton, Ohio at 10:45 AM EDT (long-deep-tired sigh)! Both flights from and to Kansas City, Missouri and Dayton, Ohio were with connections in Milwaukee, Wisconsin. The rental vehicle was a 2006 Suzuki Aerio sedan and about 1,350 miles was put on it during the entire chase tour.

MAY 23 CHASE MAIN PARTICIPANTS

CHASER NAME HOME CITY CALLSIGN CHASE DATES OCCUPATION

CHRIS COLLURA MIRAMAR, FL KG4PJN 5-22 TO 5-24 IT CONSULTANT

The participants below are not from the "Sky-Chaser" chase team. These people often actively participate in my storm research and documentation efforts and deserve appreciation for their great help and severe weather expertise.

CHASER NAME	HOME CITY	CALLSIGN	OCCUPATION
MICHAEL CARLSON	DENVER, CO	N/A	STUDENT
VERNE CARLSON	DENVER, CO	KB0ZCQ	IT

FORECASTING AND TARGET AREA

In the three images above, the Storm Prediction Center (SPC) day-one outlook products appear for the 10% hatched tornado (left) and the 45% hatched hail outlooks (middle) for 13:00z and 16:30z, respectively. The hatching denoted the possibility of a SIGNIFICANT severe weather event within 25 miles of a point (such as STRONG tornadoes of EF3 or higher, Hail 2" or bigger, and for winds 65 Knots or more). To the right is an image of the storm reports (storm events that actually DID happen) for May 23, 2007. There were 14 reports of tornadoes (red dots), 56 wind reports (blue dots plus 3 black squares for SIGNIFICANT winds over 65 Knots), and 136 reports of large hail (green dots plus 12 SIGNIFIGANT reports of hail 2" or larger denoted by black triangles). Fortunately, no signifigant tornadoes were reported.

In the diagrams above, my forecasted target area is to the left. This was my final target and is circled on the map along with my "ferry" path from Kansas into the Oklahoma / Texas panhandles. Compare this to what the Storm Predictions Center (SPC) forecasted in the two images to the center and right. In the center is the MCD (Mesoscale Discussion) product showing a region with the highest probability of severe weather. To the right, is the tornado watch box put out for the area. This watch was enhanced-worded as a PDS (particularly dangerous situation) denoting a SIGNIFIGANT severe weather / tornado event was possible. This area was relatively easy to forecast (dryline + front setup), making for a rather small target area and areal (SPC watch) outlooks.

STORM RADAR IMAGERY

The annotated diagram above shows two radar images. The left image is from the Dodge City, Kansas radar site, and the right image is from the Amarillo, Texas radar site. Both are base reflectivity. The left image shows the tornadic supercell storm near Harper County, Oklahoma at the time it was being intercepted near Laverne. The image to the right shows the later intercept of the HP supercell storms near Lipscomb, Texas.

DETAILED LOG FOR ALL CHASES

1). May 23, 5:00 PM - Observation and interception of an extremely severe (and tornadic) thunderstorm in Harper County, Oklahoma near Laverne and west of Buffalo along Highway 270 and Highway 46. This storm was a classic supercell thunderstorm developing just south of a quasi-stationary / warm front boundary and well-ahead of a dryline in very unstable air. The storm explosively developed during convective initiation (capping inversion breeched or overcome), quickly became severe, and developed a mesocyclone in a short period of time. The storm had a large, and rapidly rotating wall cloud / funnels, then (just before RFD occlusion) finally produced a brief tornado lofting tree debris over Highway 46. Partially melted hail was noted on the ground south of this storm, and was measured at golf ball (1.75") to hen's egg (half dollar, or slightly more than 2") sized. Deeper into the storm core, 6 miles west of Buffalo, softball sized hail to 4.25" was confirmed (this size was not intercepted by myself and my group). Winds near 50 MPH were also noted with the storm RFD (Rear-Flank Downdraft). The storm lasted about an hour and a half before moving north of the stationary front and weakening. Conditions producing this supercell storm were directional wind shear (surface low / upper trough), dryline and frontal boundary (ahead of triple-point), and surface heating. Documentation was still photos and HD video. A 2006 Suzuki Aerio sedan was used to chase the storm. A PDS (Particularly Dangerous Situation) tornado watch was also valid for this area until 11 PM CDT.

2). May 23, 7:00 PM - Observation and interception of another extremely severe (and possibly tornadic) thunderstorm in Lipscomb County, Texas from near Lipscomb along Highway 305 and points north / northeast. This storm was an HP supercell thunderstorm developing on the southern end of a line of thunderstorms (tail-end Charley). This storm had a large, and slowly rotating wall cloud and several funnels were observed. Some of these wall clouds were observed very close to the ground. This HP (High Precipitation) supercell lasted for roughly 3-4 hours. It had a very impressive visual appearance, with the "stacked-plates" (barber-pole) effect, and visual BWER (Bounded Weak Echo Region, or "vault"). This storm also produced exceptionally large hail, with the largest sizes encountered as big as golf balls during fringe encounters with the core of this storm. This storm also produced very powerful and frequent lightning with many close hits. When in its weakening stages / evolution to multicell cluster (MCS), winds gusting over 75-MPH were encountered on the north side of the storm (mesocyclone) with a wind shift from strong west to easterly and large hail when heading northward. This storm also produced flooding and extremely heavy rains. Conditions producing this storm were directional wind shear (surface low / upper trough), advancing dryline, and surface heating. Documentation was still photos and HD video. A 2006 Suzuki Aerio sedan was used to chase the storm. A PDS (Particularly Dangerous Situation) tornado watch was also valid for this area until 11 PM CDT.

3). May 23, 9:30 PM - Penetration of a severe thunderstorm while heading east on Highway 64 and just west of Buffalo, Oklahoma in Harper County. This storm was a multicell cluster of severe thunderstorms. Torrential rains, 60-MPH winds, frequent lightning, and hail up to nickel-sized (3/4") was encountered during the passage through this storm. This storm was part of a large MCS of thunderstorms, and was caused by outflow boundaries, frontal convergence (warm front), an upper trough, and surface heating. A 2006 Suzuki Aerio sedan was used to chase the storm. Documentation was HD video. A PDS (Particularly Dangerous Situation) tornado watch was also valid for this area until 11 PM CDT.

This concludes the chase log for Kansas, Oklahoma, and Texas (panhandles) on May 23, 2007. The summary includes a total of 3 severe thunderstorms and at least one tornado. The main chase vehicle conducting all chases was a 2006 Suzuki Aerio sedan. This information was prepared exclusively for the National Weather service and the team of Skywarn storm spotters.

GALLERY FOR MAY 23, 2007

	Preparing the chase vehicle (A 2006 Suzuki) after flying into Kansas City on May 22 and arriving in Abilene, Kansas for the previous night.
	Looking west while driving along Interstate 70 east of Salina, Kansas, the cold front stretches across the sky through the grey "grunge". Temperatures here are cool and there is much cloud cover from previous storms the night before. Ofcourse, the target area is still hundreds of miles away, where this front becomes more "positively" tilted (oriented nearly east to west rather than north to south as in this picture).
	This is not something a storm chaser likes to see. Luckily this was encountered heading south on Highway 56 in central Kansas with plenty of time to divert (detour) around and still make the target area later on. Another area of construction was also southbound on Highway 283 south of Sitka. In this case, a woman simply told everyone to "pull over to the LEFT" side of the road and wait" as there was "equipment on the bridge". About 45 minutes later, with dozens of trucks and people still waiting, the same woman simply said "I don't know" when I asked her how long the delay would be. An alternate route around that area took no more than 15 minutes. Such road construction can effectively hose-up a good chase if a chase team was rushing to meet a supercell.
	Severe thunderstorms begin developing just north of the Kansas / Oklahoma border. The cell here has an overshooting top, and is roughly 30 miles away. These storms are NOT in the target area, as they are developing along a portion of the cold front.
	Here is a view of the devastated city of Greensburg, Kansas while traveling southward along Highway 183 just north of Highway 64. An EF-5 tornado, nearly TWO MILES wide, struck this town about 3 weeks before this picture was taken (during the late-evening May 4, 2007). Disaster relief is still underway as a helicopter circles overhead.
	Here is the intersection of Highways 183 and 64. Highway 64 eastbound is closed at this point via a police checkpoint. Only disaster relief personnel, law enforcement, and residents with escorts were allowed to pass. Note the debris still strewn along the side of the road. Trucks are carrying away trees and debris to a dump and burning pit to the north of the area.
	Here is a severely damaged farmstead just west of Highway 183 and to the SSW of Greensburg, Kansas. If you look closely at the center of the picture, a large blue colored farm vehicle is flipped and most of the roof of the building is missing.
	Here is another building that was taken out by the Greensburg, Kansas tornado. To the left of the picture is a concrete slab where the building once stood. The pile of mangled material is what's left of the house / building, and lies in a heap to the right. Keep in mind, this is 3-weeks AFTER the tornado hit this area.
	In the target area of Harper County, Oklahoma, a stout buildup of cumulus makes its appearance marking convective initiation. It is now time to change from "waiting" to "chasing" and make my way towards this developing (soon-to-be) storm.
	After passing through Laverne in Harper County, Oklahoma, the relatively small cumulus towers you saw in the last picture "explode" into a full-fledged thunderstorm with an anvil. This storm developed in only 15 minutes, and is well on its way to become a supercell.
	Looking south (highway 283) at the developing storm in Harper County, Oklahoma, a developing "beaver's tail" inflow feature can be seen to the lower left as well as some "banding" to the upper right. The core of the storm is just right of the center of this picture.
	And guess who I run into when I reach the inflow side of the storm? Storm chasers! Here, father-and-son chase team Verne and Michael Carlson watch the storm with several others in Harper County, Oklahoma just south of the intersection of Highways 283 and 270. A developing supercell, especially in a small target area, acts like a "beacon" - Where storm chasers within range converge on it from all around. Normally desolate country roads actually become jammed with "chaser traffic" and caravans with many standing along the side of the road watching as if a once-a-year sporting event was taking place!
	Scientific groups are also sharing the now busy roads in a "supercell environment". In this picture, the DOW (Doppler On Wheels) vehicles race north to catch the Harper County supercell along Highway 283.
	The Harper County storm becomes more organized and begins rotating hard. This picture was taken looking northward along Highway 270 between Highways 283 and 46 near Laverne, Oklahoma. Verne Carlson is standing to the right as the storm develops a rotating wall cloud with funnels.
	One larger funnel develops on the wall cloud of the Harper County storm. I cannot tell if anything is on the ground under this feature, but it looks close!
	While driving east on Highway 270 to meet a north option on Highway 46, I see the view of the developing wall cloud / tornado in my rear-view mirror.
	The wall cloud of the Harper County storm is still rotating but I have not seen anything (such as a tornado on the ground) develop out of it yet. Continuing north on Highway 46 while the wall cloud develops a beautiful inflow tail.
	Partially melted giant hail was found on the ground behind the Harper Oklahoma supercell storm near Highway 46. Some pieces were measured at over 2" (most being the size of golf balls). This was NOT the largest hail this storm produced. Confirmed reports of softball sized hail occurred with this storm (4.25") - Ouch!
	This partially melted golf ball sized hailstone has some interesting radial "ice-cicles" on its edge.
	This is a picture of the funnel DIRECTLY under the wall cloud of the Harper County supercell near Highway 46. This picture does not do any justice on how fast the rotation was overhead. Shortly after, the storm finally tornadoed with a touch-down about 200 yards up the road (Highway 46) with a brief debris cloud and some tree debris airborne.
	This is a view of the tornado just after touching down briefly along Highway 46. The tornado (and it's parent supercell) weakened as the RFD (Rear-Flank Downdraft) occluded and the storm moved northeast into cooler air across the stalled cold / warm front boundary.
	Don't get "blown-off"! We are now headed south along Highway 283 towards Highway 60 due to a new batch of supercells near Lipscomb County, Texas. The Harper supercell has weakened and our new supercell storm is at the southern end of a line / cluster of supercells. The southern cell, called "Tail-End Charley" is often the more intense right-split. Anvil blowoff and mammatus overhead is impressive looking southward. The supercell(s) to intercept are about 30-40 miles to our WSW.
	Heading west on Highway 60, the supercell storms (in Lipscomb County, Texas) become apparent and are clearly HP (High Precipitation) supercells. Note the rotation of the "Tail-End Charley" supercell to the center and right of this picture. The striations are apparent as well as the slanting of the storm updraft due to the directional shear.
	Looking closer at the HP storm in Lipscomb County, Texas, the striated (and tilted) updraft resembles stripes on a barber pole. Chasers call this a "Barber Pole" updraft.
	Interesting mid-level shear funnel appears on one of the highly-sheared cumulus towers ahead of the supercell storms in Lipscomb County, Texas.
	The DOW (Doppler On Wheels) vehicles are parked along the side of Highway 60 just outside of Lipscomb, Texas. The other vehicles with instrumentation are from the ROTATE (Radar Observations of Tornadoes And Thunderstorms Experiment) team working with the DOW crew.
	Here is the TIV (Tornado Intercept Vehicle) also observing the storm to their northwest in Lipscomb County, Texas. This group gets close to a tornado, really close! They work with the ROTATE / DOW groups as well as getting in-situ video and / or near inflow field measurements of tornadoes if possible.
	Here is a picture (video frame-grab) of one of many tour group vans observing the Lipscomb supercell parked along highway 305. Lightning strikes behind as tourists take pictures of either me or the monster HP supercell that is behind me!
	I am not sure what I am looking at since I cannot confirm if this "feature" is on the ground or not. Nevertheless, it was rotating and could quite possible be a large tornado about 5 miles or so west of Highway 305 in Lipscomb County, Texas. Verne and Michael Carlson are in the foreground.
	Here is a view (channel 10 news is in the foreground chase vehicle to the right) of the HP supercell near Lipscomb County, Texas. I have even seen a helicopter "chasing" this storm as well as the other supercell in Harper County, OK earlier!
	Another large CG (Cloud to Ground) lightning strike while heading east on a farm road from Highway 305 to get a better look at the Lipscomb HP storm to our west - and also to stay out of the large hail.
	This is a small funnel that formed on the gust front of the wet RFD of the Lipscomb HP storm. The view is due south.
	Here is a view of the HP Supercell storm near Lipscomb, Texas. Beautiful storm structure with frequent CG lightning and "stacked plates" mesocyclone.
	This is the spectacular shelf cloud associated with the gust front of the wet RFD that was associated with the HP storm near Lipscomb, Texas.
	Amazing inflow bands just east of the HP supercell in Lipscomb County, Texas.
	At one point the Lipscomb HP storm had a spectacular vault region (clear area between precipitation to the right and updraft to the left). On radar, this creates a region of lower reflectivity and is called a BWER (Bounded Weak Echo Region). This area is also where the pargest hail is falling. The nearly vertical updraft (core) is just left of the vault, and is right over the circulation "center" of the mesocyclone. Tornadoes, if any, are hidden from view behind the wet RFD precipitation.
	Here is another picture of the vault region and HP supercell in Lipscomb County, Texas as other chasers Verne and Michael Carlson awe at the view.
	The HP supercell in Lipscomb County, Texas develops an interesting "beaver's tail" inflow feature on its northeastern side as chasers capture the show with their camera gear.
	Here is another, and closer view of the approaching gust front (and shelf cloud) of the Lipscomb, Texas HP supercell. This is associated with the gust front of the wet RFD (precipitation filled) part of the storm.
	This is a view of the laptop screen in chasers Verne and Michael Carlson's vehicle showing the Baron WX Worx radar screen with HP supercells. This is a subscription-based package, allowing real-time radar information via XM satellite, and is a bit pricey.
	This is the northeastern side of the monster HP supercell in Lipscomb County. The rotating portion of the storm, and "notch" is from the center of the picture to the left. If the storm was producing a tornado, it would be to the lower left, but is inviaible as the precipitation of the wet RFD would be obscuring it. Motion wise, feature to the left of this picture are moving left to right, but those on the right are moving right to left - Into the storm. Verne Carlson is to the right taking pictures.
	Here is another picture of the notch and incredible banding / striations of the HP supercell near Lipscomb. The notch of the storm is just below the center of this picture and "hidden" tornadoes possibly left of that area. It is very difficult (and dangerous) to try to enter this tight area of an HP supercell to see any tornadoes (called the "bear's cage"). The "stacked plates" effect gives the storm updraft a striated "space ship / flying suacer" appearance. Note the "beaver's tail" inflow feature to the lower right.
	While wrapping up the chase of May 23, the Lipscomb storm seemed to weaken somewhat, so Verne's group and myself decide to drive northwards along Highway 305. The "notch" area is just above us and a 70-80 MPH RFD wind just grazed me after I took this picture. The strong winds were from the west, then shifted to easterly just north of this area. Apparently, this is the "bear's cage" of the storm. Hail encountered was also golf ball sized with zero visibility sideways rains. The RFD in this picture also can be seen to the upper-left. INTENTIONALLY core-punching a supercell is extremely dangerous and I do not recommend it!
	The chase day ends with an incredible lightning show just before making my long drive back to Kansas City, Missouri for my flight home early the next morning.

CHASE FOR MAY 26, 2007

May 26, 2007 was a storm chase that should classify as the first official "bust" (where the atmosphere does not "cooperate" as expected) of the 2007 season. In some cases, the term "bust" can be ambiquous. Forecast-wise, May 26 looked like a great day for severe storms as a rather strong cold-core low was moving across North Dakota with a surface low southeast of it. This would set-up a warm front and cold front scenario with backed SE surface winds and 500 MB winds from the SW at 50-60 Knots. The primary target was set at the tri-state intersections of Iowa, Minnesota, and Wisconsin. With a trip to Chicago already planned for the weekend, why not spend Saturday, May 26 chasing this setup?

The initial target was set on Saturday as Lacross, Wisconsin. The chase began by leaving Dayton, Ohio on Friday, May 25 and heading west on Interstate 75 then Interstate 65 and Interstate 80 / 94 into Chicago to spend th evening. On Saturday, May 26, the target area was Lacross, Wisconsin and to get there I needed to take Interstate 90 to Interstate 39 to Rockford, Illinois then north into Madison, Wisconsin then take Interstate 90 to Lacross. Meanwhile, the Storm Prediction Center put out both their 16:30z and 20:00z convective outlooks and had a 5% tornado, 15% damaging hail, and 15% damaging wind in a slight-risk probability nearly bulls-eyed right over my primary target of Lacross, Wisconsin.

The biggest issue with this (otherwise great) setup was INSTABILITY. Cool and gloomy conditions persisted near the warm-front and over-spread a large portion of the warm sector with temperatures struggling to make the low 60's F. Once in the target area, the uneasy feeling of this unusually large cool pool of air messing up such a good setup became apparent, with the only hope of ANY storms being in a narrow axis of instability (< 500 CAPE) ahead of the cold front in late afternoon. SPC issued a Mesoscale Discussion (MCD 0897) for the area near Lacrosse and in western Wisconsin / Eastern Minnesota. The discussion also stated a watch was likely to be issued, but since instability was so limited, no watch ever was posted. All in all, only towering cumulus developed in the late afternoon in the target region. With such low CAPE, parcels were unable to reach the LFC (Level of Free Convection) and became easily toppled by the shear and / or got ahead of the warm-front boundary and became elevated and weakened.

The chase ended with only highly-sheared low-topped light showers developing. No "deep" convection. The chase ended in disappointment by returning along Interstates 90 and 39 back through Madison, Wisconsin then through Rockford, Illinois. The evening was spent in Chicago, Illinois with a return to Dayton, Ohio via Interstates 80, 65, and 70 the following day (Sunday, May 27). This chase would NOT have been attempted had previous plans to visit Chicago not been made. Total mileage for this trip was 1,305 miles.

MAY 26 CHASE MAIN PARTICIPANTS

CHASER NAME HOME CITY CALLSIGN CHASE DATES OCCUPATION

CHRIS COLLURA MIRAMAR, FL KG4PJN 5-25 To 5-27 IT CONSULTANT

GALLERY FOR MAY 26, 2007

	The target area was in the area near Lacrosse, Wisconsin, which is just across the upper Mississippi River from Minnesota (near Winona).
	Cumulus tries hard to develop despite the limited instability once the cloud-cover and cool temperatures give way to the sunshine (and heating) within a mid-level dry-slot between the cold and warm fronts. This is near Lacrosse, Wisconsin.
	This is the "storms" at their high-point. Highly-sheared and low topped cold-core type stuff. The limited instability prevented anything to really get going. The convective "cell" in this picture almost looks "LP" in nature, but it did not stay this way very long. The view is to the west from south of Interstate 90 east of Lacross, Wisconsin.
	As the sun sets and daytime heating goes away, the towering cumulus also "peters out". The cumulus tower here shows its "slanted" appearance as it is toppled over by the directional shear just before disipating.

TRAVEL MAP FOR JUNE 5-10 CHASE

In the annotated map above, the total path taken from June 5 through June 10 including target areas and chase routes can be seen. The starting (and ending) point for this chase trip was Dayton, Ohio where I was working on an off-site computer project until July of 2007. The two main target areas, also where storms were intercepted, are circled red and for June 6 and June 7. The other two targets, circled in green, were aborted since conditions never came together as required for encouraging chase prospects for June 9 and June 10. The total of all the blue "lines" on this map, if stretched to a straight line, is just under 4,207 miles over a period of 5 days. This is about the distance from New York City to western Europe.

CHASE SUMMARY FOR JUNE 5 THROUGH JUNE 10, 2007

This was a dedicated and "mini" chase expedition responding to a promising severe weather setup across the US High Plains and Midwest on June 6 and 7 of 2007, with the possibility of milder severe weather on June 9 and 10 in the central US Great Plains. Forecast models consistently pointed out the severe weather possibility from about 5 days prior to it actually occurring, and verification (it actually happening) was right-on for June 6-7, but not for June 9-10. On June 5, I left Dayton, OH just before 3 PM EDT and headed west on I-70 to Indianapolis, then northwest on I-65 to I-80 south of Chicago. The initial target was June 6 in North-Central Nebraska and possibly SW South Dakota, so Interstate 80 was taken through Iowa and Omaha, NE then west for the night stayed in York, Nebraska. This first "ferry" trip was about 840 miles from (Dayton to York) and arrival in York was about 1:30 AM CDT.

On June 6 I forecasted and looked at a primary target near Winner, South Dakota with a stop in Valentine, Nebraska. This region was ahead of a dryline bulge developing in response to lee surface cyclogenesis under a region of strong diffluent winds aloft. According to the Storm Prediction Center (SPC), a moderate risk area stretched from SW SD through central SD and southward into central Nebraska. A 10% tornado, 45% hail, and 45% damaging wind probability was set for the moderate risk, all hatched denoting probability of a significant severe weather event for all three probabilities. After leaving York, NE, I continued west on Interstate 80 to Grand Island and highway 281 to go north, then stair-stepped northwest through Nebraska's sandhills region along highways 95, 11, and 20 until in Valentine, Nebraska. A large "chaser convergence" was taking place in Valentine, as other chasers were assessing where the first storms will develop. Met up with Verne and Michael Carlson, Mike O'Keefe, Amos Magliocco, Eric Nguyen, Tony Laubach, Jim Reed, and others. On visible satellite, some cumulus was noted developing in south to southwestern South Dakota so we mobilized, and headed north on Highway 83 into SD.

While heading north on Highway 83 we (Verne Carlson, Mike O'Keefe, and myself were caravanning) noticed a cell developing to our west. This was the start of a "beacon" supercell storm attracting chasers from miles around! We headed west on Highway 44 towards Wanblee, South Dakota in the Big Pine Indian Reservation. While approaching the supercell storm, a tornado was observed from a distance on this supercell storm's updraft region. The tornado was also observed stopped from atop a hill in Wanblee. This tornado (Shannon County) lasted roughly 25 minutes, and its latter life cycle was observed from near Wanblee from a distance of roughly 10-15 miles. The supercell storm evolved to HP mode, then an extremely intense bow segment afterwards, warranting a hasty retreat back along Highway 44 to Highway 73 then north to Kadoka, SD then east on Interstate 90. Another possible tornado, although highly precipitation-wrapped, was observed southwest of Kadoka along highway 73. There were nearly 100 storm chasers in this area, including the TIV (Tornado Intercept Vehicle) and DOW (Doppler On Wheels) research teams. Semis were also blown over on I-90 from the 70-80 MPH outflow winds as the storms went to a bow-segment. When continuing east on Interstate 90, the previous storms weakened and attention focused towards another round of storms developing near the dryline bulge to the southeast. The chase headed to Highway 183 to Winner, SD then south to near Basset, Nebraska.

The second round of storms quickly developed but into a line of storms by dark. I wrapped up the day by heading east on Highway 20 to Highway 137 to go north, then Highway 12 to take Highway 281 back north into South Dakota. I met up with Tony Laubach, Eric Nguyen, and Amos Magliocco for the night's stay in Wagner, South Dakota along Highway 46. The chase for June 7 basically followed the potent upper air / surface system eastward for quite a ways. Not much forecasting was required for this day, but SPC (Storm Prediction Center) had a frightening high-risk outlook for eastern Minnesota, much of Wisconsin, and extreme Northeastern Iowa and Northern Illinois. In this high-risk outlook, tornado probability was 30%, hail was 45%, and wind damage was a whopping 60%, all hatched for "significant" severe weather. Another interesting note was that the surface low was from 975 to 980 MB with a low-level jet stream in excess of 80 knots ahead of the dryline. This meant for lots of shear, but very fast storm motions, making chasing difficult. The chase left Wagner, along with Tony Laubach (Amos and Eric did not chase this day), heading east on Highway 46 to Interstate 29, then north to Sioux Falls, SD to take Interstate 90 east across Minnesota.

Storms initiated east of Albert Lea, Minnesota at around 1:30 PM CDT just as PDS tornado watch 360 for a previous mesoscale discussion was issued for our target area. The storms began as a multicell cluster / line but soon evolved into discrete supercell storms. One supercell storm was noted developing on the NW side of this cluster just as the dryline was crossed. The dryline passage was denoted by strong SW winds and dust to its west and a dewpoint jump from 42 degrees to 72 degrees across a distance of only 10-15 miles! The supercell storm to the north of Interstate 90 was highly sheared and a possible tornado was noted under it's base from a great distance. This was to be the northern supercell storm that caused significant damage later near Ried, Wisconsin around 4 PM, CDT. Continuing east on I-90 and headed across the squall line itself into Lacrosse, Wisconsin a few severe storms were noted. While navigating along Highways 61 and 33 (where 33 was partially closed due to construction), a supercell storm developed near Lacross, Wisconsin and moved rapidly to the Northeast. We headed north on Highway 162 then east on Interstate 90 once behind the rapidly moving storm. The storm had an impressive RFD slot, a wall cloud / funnels, and already produced hail up to 3" near Lacross.

Attempting and trying as hard as we could to keep up with this supercell, we headed east to I-94, jogged northwest a bit, then took Highway 173 northeast towards the supercell's rear-flank. At roughly 4:30 PM CDT, the tornado reported near Wisconsin Rapids, Wisconsin was observed through heavily wooded terrain from a distance of roughly 10 miles. The supercell storm had a completely eroded RFD (rear flank downdraft) dry-slot making the tornado and wall cloud visible. The chase of this fast moving storm was forfeited upon arrival into Wisconsin Rapids, where trees and powerlines were down on County Road G southwest of town in Port Edwards. Once in Wisconsin Rapids, some of the largest hail I ever seen (or imagined) was encountered. Tony and I measured hail over 4", even after partial melting, covering the ground in a residential area. Car damage was heavy and many leaves / branches were stripped off trees. The hail was also large enough to put holes in a roof and leave deep craters in the ground! Tornado-like damage also was reported on the southeastern side of Wisconsin Rapids. This was not a supercell storm you would like to get ahead of and have it's core pass over you - Hail officially measured at 4.25" (slightly larger than a grape-fruit and a bit smaller than a coconut) can kill.

After taking a break from the storms in Wisconsin Rapids and observing hail damage, we continued out on Highway 13 then Highway 73 to take Interstate 39 southward to check out more possible storms developing in NE Iowa and Northern Illinois. When in Illinois, and near Rochelle, a cluster of severe storms was encountered. While stopped to shoot lightning photography, one severe cell ahead of this line acquired supercell characteristics, and a funnel / possibly brief tornado was captured by time-exposure before getting hit with RFD precipitation and warranting a hasty retreat to continue back south on I-39. The chase was wrapped up and spent in Normal, Illinois for the night. According for forecasting, and in the wake of the potent system from the past 2 days which was exiting the USA and entering NE Canada, Tony and I decided to target western Kansas as a last long-shot prospect for June 9 and June 10 with June 8 being a down / travel day. On June 8, I left Normal, Illinois and headed solo to Saint Louis, MO along Interstate 55 to Interstate 70 to begin heading west.

I stopped for a doctor's appointment in O'Fallon, MO at a walk-in clinic to pick up a prescription, forecasted a bit, took care of some personal business, and continued west along I-70 stopping to meet a friend of mine in Kansas City, MO then well into Kansas to Wakeeney for the night, meeting back up with Tony Laubach there. To our disappointment, the storm prospects for western Kansas on June 9 and into central / eastern Kansas changed radically from previous models / SPC outlooks. Both target areas for June 9 and 10 in Kansas had to be foregoed as the only storm prospects changed to extreme SW New Mexico for June 9 and the Dakota regions for June 10. This was because a cut-off low off the SW United States did not develop as expected, and limited moisture was draped across the central USA. Some storms did actually occur on June 9 and 10, but the chase prospects for them did not look very encouraging. I left Wakeeney, Kansas and made my long trip back to Kansas City, Missouri on the morning of June 9. Since it was a weekend, I decided to divert a bit north on Interstate 35 to Interstate 80 across Iowa and into Illinois (Interstate 255) to spend the night in Chicago, Illinois and do some sight-seeing there. I left Chicago, Illinois on June 10 and headed to Indianapolis using Interstates 90 then 65, and made the final leg into Dayton, Ohio via Interstate 70 (Dayton is off Interstate 75) to wrap up this interesting road trip from June 5-10, 2007. The total mileage, using my person vehicle - A 2007 Ford Focus - Was just under 4,207 miles.

JUNE 5 TO JUNE 10 CHASE MAIN PARTICIPANTS

CHASER NAME HOME CITY CALLSIGN CHASE DATES OCCUPATION

CHRIS COLLURA MIRAMAR, FL KG4PJN 6-5 TO 6-10 IT CONSULTANT

CHASER NAME	HOME CITY	CALLSIGN	OCCUPATION
AMOS MAGLIOCCO	BLOOMINGTON, IN	KC5VPD	WRITER
ERIC NGUYEN	NORMAN, OK	KD5HPZ	METEOROLOGIST
TONY LAUBACH	LITTLETON, CO	KC0ONL	STUDENT
VERNE CARLSON	DENVER, CO	KB0ZCQ	IT

FORECASTING AND TARGET AREA - JUNE 6

In the three images above, the setup and effects on June 6, 2007 are portrayed. To the far left is an enhanced water-vapor image of an unusually strong upper-level low (500 MB) over the American Rocky Mountains. This system is responsible for about 3 days of severe weather across the northern USA plains and midwest regions as a surface low develops in the lee of the Rockies (lee cyclogenesis). The middle picture is MCD (mesoscale discussion) 1026 placed over the region where the lee cyclogensis is occurring, and points to a high probability of tornadic supercell formation near the areas of SW South Dakota. This is the same area targeted for the chase on June 6, 2007. To the right is the actual storm reports for June 6, where a blue dot represents severe winds, a green dot represents large hail, and each red dot represents a reported tornado. One of the red "dots" in SW South Dakota was our tornado we intercepted near Wanblee, SD during the afternoon of June 6.

STORM RADAR IMAGERY - JUNE 6

The annotated diagram above shows two radar images from the Rapid City, South Dakota radar site. The image to the left shows radar base reflectivity and the right image shows the storm velocity (Doppler based). In the reflectivity image on the left, a supercell storm (HP in nature) can be seen transitioning to a very well-defined bow echo. To the right, a velocity couplet denotes an area of rotation within the leading edge of the bowing supercell storm. This is the same region during the time the long-lived tornado was occurring southwest of Wanblee, SD during the afternoon on June 6.

FORECASTING AND TARGET AREA - JUNE 7

The three images above show the setup and storm report details, provided by the Storm Prediction Center (SPC) for June 7, 2007. To the left is the tornado probability in an a high-risk outlook, with a frightening 30% hatched outlook centered on Wisconsin. The middle image is PDS (particularly dangerous situation) tornado watch-box (watch #360) issued by SPC for the area the chasing was done in for June 7. The image to the right is for the actual storm reports for June 7, where a blue dot represents severe winds, a green dot represents large hail, and each red dot represents a reported tornado. Also note that the black square and black triangle represents a significant wind or hail event, respectively. Obviously, a red "dot" and black "triangle" mark one of the violent supercells intercepted in Wisconsin during the afternoon of June 7.

STORM RADAR IMAGERY - JUNE 7

The annotated diagram above shows two radar images from the Lacross, Wisconsin radar site during the afternoon of June 7, 2007. The image to the left shows radar base reflectivity and the right image shows the storm Doppler velocity. In the reflectivity image on the left, a supercell storm has formed. If you look closely, you can make-out a hook echo on the suthern side of this storm just when it was near Wisconsin Rapids, Wisconsin. In the right image, a velocity couplet can be seen in the same storm. This supercell was moving northeast at a whopping 60-MPH+ and was one of two violent supercell storms that produced tornadoes. The storms in these images also produced hail larger than grapefruit-sized (up to 4.25")!

JUNE 7 TORNADO "SCRATCHES" THE FACE OF THE EARTH!

The annotated diagram above shows two satellite images taken of the state of Wisconsin after the June 7, 2007 storms (and destructive tornadoes) passed over that state. The left image is from afar and the right one is a close-up. The unmistakable "scratch mark" of a 3/4 mile wide tornado, from the same storm that formed near Lacrosse, then produced a tornado that first struck Wisconsin Rapids (which is out of frame but far lower-left of the left picture), and went on to cause a long damage path to the northeast. Seeing a mark like this from space hints on the forest-leveling power of a tornado, which fortunately tore up mostly uninhabited rural countryside until hitting some buildings in an Indian reservation. From way out in space, we see one more little "scratch", oriented SW to NE, on the face of our planet.

DETAILED LOG ALL CHASES

1). June 6, 4:30 PM - Interception of a very severe thunderstorm and tornado southwest of Wanblee, South Dakota near Shannon County from Highway 44. The storm was a supercell storm that originally began as a classic supercell then evolved to HP mode and subsequent bow echo (intense multicell cluster) there-after. This storm produced a long lived dusty tube type tornado in Shannon County at around 4:30 PM MDT. The latter cycle of this tornado was observed from near Wanblee at a distance of 10-15 miles. The supercell storm occluded and a new mesocyclone developed to the east of the previous (tornadic) one but only produced some funnel clouds. The storm evolved to HP, and produced another barely-visible rain-wrapped tornado southwest of Kadoka, SD before the storm quickly evolved to a bow-echo structure. Both tornadoes occurred over un-populated areas so damage was not observable. The cores of the supercell / bow were not penetrated but winds exceeding 70-MPH and hail up to 1" was encountered on the fringes of the storm. Damage observed was to trees and powerlines, and included a semi-truck blown over in Interstate 90 near Murdo, South Dakota. Conditions producing the storms were a strong low-pressure system, dryline / boundary interactions, surface heating, intense upper-level system / jet stream aloft, and possible up-slope (southeast) wind flow. Documentation was still digital pictures, HD video, and SD video. A 2007 Ford Focus was used to chase the storms. A PDS Tornado Watch was also valid for this area until 11 PM CDT (10 PM MDT).

2). June 7, 3:30 PM - External observation of a very severe and tornadic developing supercell thunderstorm from Interstate 90 in eastern Minnesota (northeast of Rochester and northwest of Winona). This developing storm was observed from a distance of about 15 miles at it's point of closest approach and was not penetrated. Viewing the rear-flank of this highly-sheared storm, a well-defined rear flank downdraft (RFD) clear slot was noted along with a large funnel / tornado like lowering. This is also the same storm that produced tornado damage near Ried, Wisconsin a couple of hours later. Conditions producing this storm were a strong low pressure system and attendant dryline, surface heating, very strong winds / jet stream aloft, and abundant moisture. Documentation was still digital photos. A 2007 Ford Focus was used to chase the storms. A PDS tornado watch was also valid for this area until 12 AM CDT.

3). June 7, 5:00 PM - Interception and observation of an extremely severe and tornadic thunderstorm from Lacross, Wisconsin northeastward into Wisconsin Rapids along and near highway 173. This storm was a violent supercell (classic) thunderstorm that produced a tornado that struck part of Wisconsin Rapids and affected the area with hail exceeding 4 inches in diameter. The tornado from this storm was observed from a distance of 10 miles, behind an impressive and large RFD clear-slot on the rear-flank of this supercell. This storm was moving northeast at over 60-MPH, so getting "ahead" of it was not an option. Fortunate to the fact that hail exceeding 4" in diameter, although partially melted, was found covering the ground on the southwest side of Wisconsin Rapids. Damage from this hail was extensive, including many cars damaged or destroyed, holes punched in roofs, many trees stripped of leaves and twigs, and even deep craters left in the ground. The largest "gorilla" hail was set at 4.25" (a bit larger than a grapefruit or softball). The tornado path was not observed but was just east of where the largest hail feel. Trees and powerlines down were also encountered with power knocked out. Conditions producing this storm were a strong low pressure system and attendant dryline, surface heating, very strong winds / jet stream aloft, and abundant moisture. Documentation was still digital photos and HD video. A 2007 Ford Focus was used to chase the storms. A PDS tornado watch was also valid for this area until 12 AM CDT.

4). June 7, 10:00 PM - Interception and observation of another severe and possibly tornadic thunderstorm just west of Interstate 39 near the town of Rochelle, Illinois. This storm appeared to be on the leading edge of a cluster of severe thunderstorms earlier moving eastward out of eastern Iowa. The main focus on this storm was lightning photography, but interesting banding and "stacked plate" structure of the storm was revealed by lightning and digital camera time exposures. The storm appeared to be a small classic supercell storm, and a funnel cloud / possible brief tornado was observed (via time-exposure photography) illuminated by both lightning and the lights from nearby Rochelle. This "area" passed to our north and an RFD (rear-flank downdraft) hooked around it, with small hail and winds over 50-MPH. Later analysis of the imagery from this storm revealed a mesocyclone was indeed present and a tornado / funnel cloud clearly presented in time-exposure images. Conditions producing this storm were a strong low pressure system and attendant dryline, surface heating, very strong winds / jet stream aloft, and abundant moisture. Documentation was still digital photos and HD video. A 2007 Ford Focus was used to chase the storms. A PDS tornado watch was also valid for this area until 12 AM CDT.

This concludes the Chase Log for the northern US Plains and Midwest tornado chase trip from June 5 through June 10, 2007. The summary includes a total of 4 severe thunderstorms, all of which produced tornadoes or funnel clouds. A total of 5 tornadoes were observed, two of which were confirmed. The main chase vehicle conducting all chases was a 2007 Ford Focus. This information was prepared exclusively for the National Weather service and the team of Skywarn storm spotters.

GALLERY FOR JUNE 6, 2007

	This is a picture of a motel parking lot in Valentine, Nebraska during the early afternoon of June 6, 2007. Several chase teams have "just happened" to meet here from miles around since this was a major stopping point within a chase target area. Chasers call this a "chaser convergence". In this picture, Jim Reed, Verne Carlson, Amos Magliocco, and Eric Nguyen are amongst others talking about where to go next (preferably to the northwest into South Dakota).
	A Japanese TV documentary group who was chasing with Verne Carlson and his son Michael left this in the back of their chase vehicle. This is a tornado video probe containing 4 cameras (three looking left, right, and front, and one looking straight up. The entire unit is housed in a bullet-proof steel enclosure and each window is bullet proof glass. The cameras run off a common power supply in addition to their own batteries. Verne has yet to deploy this gadget in the elusive path of a tornado, but the Japanese crew was nice enough to foot his expenses to do so (paid for his gas, lodging, etc).
	While heading northward on Highway 83 in South Dakota, a developing supercell thunderstorm appears on the horizon. This shot is highly zoomed in, as the storm is over 50 miles away. Chasers call this single storm that develops in a target area a "beacon", as it attracts storm chasers anywhere in sight of it for many miles around. The ultimate chaser "convergence" often will occur when storm chasers reach this storm - Turning rural roads into traffic jams of storm chaser caravans! This is the storm that will eventually grow and produce a tornado in Shannon County, South Dakota. The view is to the west.
	A dusty rope tornado appears under the base of the supercell storm in Shannon County, South Dakota. This tornado is about 10-15 miles southwest of the town of Wanblee in the Pine Indian Reservation, and is being viewed from a hilltop. This tornado lasted about 25 minutes, and moved slowly despite insane upper level windflow. This picture was taken at the last 5 minutes or so before the tornado lifted. The view is to the southwest.
	This is the same picture of the tornado above, but with the region of interest highly contrasted for a better view of the tornado on the ground.
	Impressive banding and lowering appears with the low-level mesocyclone of the supercell moving towards Wanblee, South Dakota. This picture shows the wall cloud (evolving to an RFD shelf cloud) as the mesocyclone that produced the Shannon County tornado occluded. Note the RFD clear slot wrapping completely around the mesocyclone and coming into the upper left side of the picture. A new mesocyclone is forming to the left. The view is southwest.
	Here is a closer look at the new mesocyclone that developed just to the east of the old one that produced the tornado. This cycle did not produce a tornado, but these rotating funnel clouds. The low level banding is very impressive and clearly marks the rotating portion of the supercell. The view is to the south.
	The RFD gust front from the first two mesocyclones occludes and cuts off the areas of rotation, and the storm becomes more precipitation-efficient, making it evolve from a classic supercell to an HP (high precipitation) supercell storm. This is a view of the RFD gust front, now with a precipitation core behind it, pushing out and forming a "notch" where a new mesocyclone is developing. The "notch" area is behind the lowering to the right. The view is to the west and northwest.
	The tornado intercept vehicle (TIV) drives by as other storm chasers watch the storm evolution near Wanblee, South Dakota along Highway 44. The normally desolate regions of South Dakota's badlands became a congested arena for many storm chaser vehicles, many from bonafide research groups as well.
	This is a view of the HP supercell storm from Highway 44 southwest of Kadoka, SD. At this time the storm was producing a tornado wrapped in precipitation (you can barely make out its silhouette hidden behind the intense rain hook). The view is to the west-northwest at the "notch" of the HP supercell. The canyons and buttes in the foreground is South Dakota's badlands.
	This is Highway 44 through South Dakota's badlands with a line of chasers. The DOW (Doppler On Wheels) vehicle is in the front scanning the tornadic HP storm southwest of Kadoka, SD.
	While racing eastward out of Kadoka, SD on Interstate 90, the storm gust front blasts outwards producing winds well over 70-MPH. This is a view to the south on what the shelf cloud looked like as it was keeping up with my vehicle. The storm at this point has evolved from an HP supercell to what is known as a "bow echo" as it takes a "bow shape" on weather radar. A forward flank "funnel" can also be seen on the lower-right side of this picture.
	Here is another view of the leading edge of the intense bow segment near Murdo, SD from along Interstate 90. A forward-flank mesocyclone is to the lower-left side of this picture and has caused a "kink" in the gust front and shelf cloud. This picture is not contrast-enhanced, this is actually what the storm looked like visually. The view is to the northwest.
	Here is the gust front and outflow winds hitting a truck-stop near Murdo, SD and just north of Interstate 90. Winds over 70-MPH, preceding the precipitation core, kick up lots of dust.
	This is a tractor-trailer semi that has been blown over by the violent outflow winds and is lying on its side in the median of Interstate 90 east of Murdo, South Dakota.
	The dryline is a boundary between warm moist air and warm dry air in response to downslope flow in the central US just east of the Rocky Mountains near surface low pressure. This is often accompanied by a wind shift from SE to SW and a sharp drop in dewpoint (humidity) as the dryline passes. Storms often develop ahead of such a boundary. In this picture, looking west, the dryline is clearly marked by a "stop" in the foreground clouds. Behind the dryline, in the warm and much drier air, dust is often kicked up and can be seen to the right.
	An impressive display of mammatus clouds appears at sunset behind an MCS of strong and severe storms pushing through north-central Nebraska. These clouds are not tornado-producers by themselves, but present extreme turbulence aloft.
	This is a video frame capture of some cloud-to-cloud lightning (CC) on the backside of the MCS pushing through north-central Nebraska.

GALLERY FOR JUNE 7, 2007

	Heading east on Interstate 90 through southern Minnesota, the initiation of strong and severe thunderstorms appears as a large buildup of cumulus clouds to our east. This was the high-risk day where tornadic supercells developed into Wisconsin. Chase partner Tony Laubach is in the vehicle ahead of me.
	The storms quicky become severe and organize into a line segment just ahead of the surface dryline, which has now punched its away all the way into eastern Minnesota! The view is to the southeast, and a large supercell storm can be seen to the right, on the southern end of the line (called a "tail-end charley" storm).
	While crossing the dryline boundary from west to east in eastern Minnesota along I-90, the sudden shift of wind from southwest to southeast is so rapid that dust is kicked up on the backside of the dryline boundary. The surface dewpoint also went from 42 degrees F to 72 degrees F in only 10-15 miles of eastward progression across the dryline boundary. Very impressive for this far east.
	Here is another view, looking west, of the dryline boundary in eastern Minnesota. The moisture decreases as you progress westward, and the line of cumulus in the upper part of the picture "stops" at the dryline boundary itself.
	A highly sheared supercell storm develops on the backside and northwestern portion of the cluster / line segment of storms near the Minnesota / Wisconsin border. This storm will eventually separate from the line and move discretely and produce tornado damage near Ried, Wisconsin. The view here is to the north and northeast. Note the extreme tilting of the updraft due to the extreme shear.
	Here is another picture, looking the other direction (southeast) towards the "tail-end charley" supercell at the southern edge of the line segment. Very impressive and rock-hard cumulonimbus structure. Note the knuckes (back-sheared anvil) and overshooting top.
	A closer view of the highly-sheared supercell rear-flank and base north of I-90 near the Wisconsin / Minnesota border (northwest of Winona and northeast of Rochester) reveals this possible tornado / large funnel and an impressive RFD slot. This view is to the north and the possible tornado is about 15 miles, or more, away.
	Interesting band of extremely fast-moving low clouds behind the MCS and feeding into the storm north of Winona, Minnesota while heading east on I-90. The low-level jet stream has winds in excess of 80 knots this day from the south, while winds aloft at 300 MB were WSW at over 125 Knots. The dark sky in the background is from the anvil shadow of the storms / supercells associated with the cluster of storms entering Wisconsin.
	This is the beginning of the supercell storm that began near Lacross, Wisconsin and was to go on and produce extremely large hail and a tornado near Wisconsin Rapids later on. In this picture, looking northwest towards Lacrosse, a wet RFD has formed and is loaded with large hail (up to 3"). The developing tornado is not visible but should be behind the rain "hook" and just left of the center of this picture.
	As the storm clears Lacrosse, Wisconsin, it begins accelerating to the northeast and makes its way towards Wisconsin Rapids. The view here is to the northeast from I-90 and shows an extremely large RFD clear-slot and wall cloud / tornado on the ground behind it.
	Possible tornado on the ground (highy zoomed shot) while looking northeast along highway 173. This is about the same time Wisconsin Rapids, WI (10-15 miles away from where this picture was taken). was being hit with a tornado.
	Baseball to grapefruit sized hail is scattered across someone's front lawn southwest of Wisconsin Rapids, Wisconsin as the tornadic supercell moved through about 5 minutes earlier. At this point the chase is hosed as the storm is moving too fast to catch up with after running into downed powerlines and damage in Wisconsin Rapids.
	Here is a picture of myself holding large "gorilla" hailstones on the southwest side of Wisconsin Rapids, Wisconsin. Tony Laubach and I took these pictures of the hail and video was fed to CNN as well.
	Here is another shot of two large hailstones. The stone to the left had an odd shape and was elongated, possibly by the stones attitude (pointing in a certain direction) during free-fall from so high up.
	A very large (4" or more) piece of hail that is partially melted. This particular hailstone is actually made up of several smaller stones that contaced each other and stuck / froze together while at high altitude inside the supercell.
	Some large hailstones, still large after partial melting, compared to a $20 bill.
	This young women's brand-new car was severely damaged by the Wisconsin Rapids hailfall. Three large shatter marks can be seen in the windshield along with numerous hail dents and a headlight destroyed.
	The rear window of this Wisconsin Rapids resident's car was also destroyed. The hail also fell with a horizontal "throw" (freefall drift) because of the fast motion of the supercell and strong winds in the storm's core. Many vehicles and homes had damage only on their windward facing sides. One resident had holes through his roof and water leaking into his attic!
	This is a crater left in the ground in a Wisconsin Rapids resident's front lawn from one of many giant hailstone impacts. The melted stone removed from the crater is just above the hole in this picture. Hail this big hitting someone can seriously injure and / or kill them.
	Here is a picture of another discrete supercell storm moving off into central Wisconsin at a distance of about 35 miles. The view is to the east. Also note that this supercell is undergoing a splitting phase.
	This is a digital time-exposure of two nice cloud to earth (CG) lightning strikes taken during the late evening near Rochelle, Illinois just west of Interstate 39. The storm is about 10 miles away in this picture, which is looking west.
	As the storm moves a bit closer, a mesocyclone develops, and CG lightning illuminates its shape and banding associated with it. This is now a small supercell storm, and is about 5 miles away. At this point, with the rear-flank of the storm about to pass over Rochelle, interest changes from shooting lightning time-exposures to worrying about possible tornado development.
	Sure enough, and through time exposure photography, a funnel cloud appears (center of picture) on the rear-flank part of the storm near Rochelle, Illinois. This is extremely dangerous, especially in a high-risk watch box and at night. The lights from Rochelle were enough to expose this time-exposure and reveal this dangerous feature. Shortly after, the funnel moved to our north and we got hit with the RFD / rain hook and 50-MPH winds and small hail ensued.
	Here is an enhanced time-exposure and close up of the funnel / possible tornado from the storm north of Rochelle, Illinois just before being hit with the RFD.

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