The storm chase expedition to the US Great Plains for 2006 took place from May 17 through May 31 of 2006 and has been completed. There was a total of 15 travel days, of which, 14 of these days were available for chasing (day 15 was a travel day). In these days, there was 9 chase days, 5 travel / down days, and 1 "bust" day. The storm intercept team involved this year consisted only of myself and was be "based" out of Oklahoma City, Oklahoma where I flew out to on May 17, 2006 and chase until May 31, 2006. This was my seventh trip dedicated to severe thunderstorm research in this area, which includes the Great Plains and the Midwestern United States. 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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The participants below often actively participate in our storm research efforts and deserve appreciation for their great help and severe weather expertise.


Please note that several other chasers may caravan or "converge" with us.


The map above shows how much territory was covered by myself chasing solo in the central United States during Chase expedition 2006. About 12 states were covered (note that the flight from Dallas, TX to Oklahoma City, OK is not shown) over a period of 15 days. The paths traveled are in yellow lines and the yellow circles are where storms were intercepted. An incredible area was covered, stratching from southwestern Oklahoma and northeastern Colorado eastward to western Ohio as well as from central Oklahoma northward to extreme northern North Dakota at the Canadian border!



The following entries are all storm chases and interceptions performed in the Midwest United States from May 17, 2006 to May 31, 2006. This log is based on a solo effort of a storm chasing team. Members were myself - Chris Collura (Florida Skywarn storm spotter code B036 - KG4PJN). The main chase vehicle was a 2007 Ford Focus rental. States chased (includes travel states): CO, IA, IN, IL, KS, MN, MO, ND, NE, OH, OK, SD, and TX (13 states). Total mileage: 8,337 Miles (about the same distance from Las Angeles to Tokyo)!

Communications employed are HF and VHF HAM radio, FRS hand-held radios, wireless Internet, and cellular phones. Most importantly, the ability to shoot HIGH DEFINITION video is once again possible on this trip! We also used other state-of-the-art video and camera gear, GPS, and a laptop computer for navigation, video / photo editing, and Internet. The main chase duties are shifts in navigation using the GPS, radio communications, driving many miles, editing footage, and preparing forecast data. A newly re-designed portable weather station, also designed by myself, has been completed and was once again employed.

I flew into Oklahoma City, Oklahoma on May 17, 2006 in the mid morning (around 11:30 AM) and to pick up the rental vehicle. From there I headed to my first "target area" in Missouri / Indiana on May 18. My return flight on May 31, 2006 left Oklahoma City and returned to Florida concluding the trip. The chase involved large expanses of the US Great Plains sometimes in the worst driving conditions imaginable, even in very remote regions.

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.


May 17 - Arrival day. Arrived at Oklahoma City and picked up rental vehicle. Anticipating a few days of "down time" (no storms) I decided to head east on I-44 to spend the night in St Louis, Missouri. The only possibility of weak convection also happens to be in and east of the St Louis area before activity returns to the high plains in a few days.

May 18 - Today was expected to be a total down day which the first half of which was spent in Saint Louis, Missouri killing time. By afternoon, convection began east of the area with enhanced cumulus developing. After checking data and seeing an upper air disturbance moving across eastern and central Illinois and into Indiana, I decided to investigate any convection that might develop. In low dewpoint air, and despite a stiff northwest flow at the surface and aloft, some strong thunderstorms did get going, one of which was intercepted on Interstate 70 near Brazil, Indiana. Time-lape video was also produced for the remainder of the convection. Day was wrapped up for the night in Indianapolis, Indiana. This was the farthest east I ever chased and plans are to head back west for activity in a few days back in the high plains.

May 19 - Down day, with only slight chase prospects dwindling in the extreme southern portions of Illinois and Indiana, I decided to kill more down time with a visit and stay over in Chicago, Illinois since it was about 3 hours northwest of Indianapolis. I also forecasted and found that portions of MO and Kansas may have fair to good chasing prospects for the next day (May 20).

May 20 - Cap bust day. I decided to gamble by side tracking into SW Missouri near Cassville off Interstate 44 (since I had to head back west anyways) after seeing a moderate upper-air impulse sliding SE in the NW flow aloft with a pocket of high CAPE and boundary enhanced helicity (from a stationary front across southern MO) in that region. The only thing was the 700 mb temperatures were too warm, and a capping inversion held solid from the NE side of a 500 mb thermal ridge (to my SW). Waited for any signs of development until about 6:30 PM CDT and nothing happened, despite nearly a 20 degree difference (92 in Cassville with SW winds and 73 near Carthage with SE winds, 40 miles apart). Only elevated showers were observed north of the boundary due to the upper-air disturbance and associated large-scale ascent. Headed north on highway 77 and spent the evening in Harrisonville, MO. The next day (5-21) may be a chase day in western Kansas based on looking at data that evening of May 20.

May 21 - Chase day with two thunderstorms intercepted, one a supercell near Springfield, MO and the other a strong multicell storm near Plad, MO. Today had a nearly identical setup as the one on 5-20 near Springfield, MO so after much forecasting I decided to target that area rather than head west. This time, the cap was overcome since a mid-level MCV was rotating eastward out of central Kansas and two boundaries were in place over the target area. After the interception(s), I headed back to Salina, KS for the night anticipating a drive farther west on 5-22 for possible upslope convection in NE Colorado / NW Kansas.

May 22 - Today was a chase day with good potential which did not come together fully. Began the day by leaving Salina, Kansas after looking at data and forecasting a region of convergence / upslope in NE Colorado / NW Kansas under an approaching shortwave. Headed northwest on Interstate 70 then north to first target area of Wray, Colorado near the tri-state regions of CO, NE, and KS. Storms did develop in that region, but were very high based as dewpoints never reached that region and the upper dynamics had not cleared the Rocky Mountains in time. The storms were strong thunderstorms, one exhibiting weak rotation, but did not get organized. Met up with several other chasers, including Brian Morganti and Jeff Pitrowski and even did a demo of my equipment / interview for a Brazilian film crew riding along with Brian's group. Headed back east to North Platte, NE for dinner and to spend the evening as the next day (5-23) should be another chase day farther east in Nebraska along Interstate 80.

May 23 - Chase day in southeastern South Dakota where high chase prospects wound up with an outflow dominant squall line and many intense gustnadoes. Left North Platte after forecasting and found the best target to be near Chamberlain, South Dakota and nearby areas to the southeast along Interstate 90. Initiation of storms began as expected in the target area by afternoon and continued eastward along Interstate 90 where I met up with other chasers including Tony Laubach near Kimball, SD. The storms became linear and with very strong outflow winds, but a fantastic spree of gustnadoes was caught not far from Letcher, South Dakota ahead of the squall line. The storms encountered also had strong winds and heavy rains. The chase track played the squall line looking for circulations and forward-flank mesocyclones in the gust front. Todays long chase track, once out of Nebraska and into South Dakota, contined east along Interstate 90 into extreme SW Minnesota, then south on Highway 75 into Iowa where Tony Laubach and myself spent the night in Sioux City, Iowa.

May 24 - Today was a long chase day which began early with a forecast that targeted east-central Iowa and west-central Illinois. Tony Laubach and I left Sioux City, Iowa and headed south on Interstate 29 then East on Interstate 680 and 80. We passed Des Moines, Iowa then dropped southeast on Highway 163 into Ottumwa, Iowa where we checked data and met up with a few other chasers. We continued east on Highway 34 into Illinois. With another check of data, we continued to Galesburg, Illinois then north on Interstate 74 to finally intercept developing storms southeast of Moline, Illinois. The storm briefly became a small supercell near Rock Falls, Illinois before splitting and evolving into a multicell line and gusting out. We headed southeast on Highway 52, then to Interstate 39 to wrap up the day with dinner and lodging in Bloomington-Normal, Illinois.

May 25 - Another chase day beginning with Tony Laubach and myself forecasting and targeting east-central Indiana from Indianapolis to the Ohio border as tghe primary target. We left Bloomington-Normal, Illinois and headed east into Indiana towards Indianapolis and stopped at an exit off Interstate 70 where we met another chaser, David Diehl. We continued south towards Eminance, Indiana then towards Bloomington where the first tornado-warned supercell storm was found near Elletsville, Indiana producing small funnel clouds. The storm merged into a squall line so we headed back north and around to the east side of Indianapolis to try to get ahead of the storms, but they became linear and outflow dominant. We continued to the Ohio state line and ended the chase there. I continued back west towards Inidianapolis as Dave and Tony split apart as well. As I continued west, I encountered another severe storm with a spectatular shelf cloud (also outflow dominant) near Interstate 70 near Spiceland, Indiana. The storms continued to become linear, and I wrapped up the day spending the night in Indianapolis,l Indiana.

May 26 - Today was taken to be a travel (down) day to re-position farther west anticipating the next disturbance moving into the high plains. Left Indianapolis, Indiana and headed west on Interstate 70 most of the day and spent the night in Kansas City on the Kansas side. The original plan was to pass "down time" in Chicago, Illinois but plans changed as the rule was to head west. Unfortunately, major storms were missed this day in the western Kansas region as the "new" disturbance was much stronger than forecasts and models depicted. The next day should have activity and Kansas City at least puts any new chase prospects in range.

May 27 - Today was a long shot, a real long shot, which began with a forecast pinpointing the best chance of tornadoes and severe storms in northeastern North Dakota, and I made the trip. I left Kansas City, Kansas at 8:30 AM and headed up highway 29 through Kansas / Missouri, Omaha, Nebraska (where some strong storms were passed by), Sioux City, Iowa then into South Dakota and North Dakota choosing Fargo, North Dakota for the first target. The trip took about 7 hours, and I was in Fargo by 3:30 PM. Upon checking data, the best dynamics and chance of initiation (enhanced cumulus revealed by visible satellite) was about 100 miles to my west, so I headed west on Interstate 94 and found a line of towering cumulus far off to my NW. I headed north on Highway 231 out of Jamestown, North Dakota as the towering cumulus developed into a distant building supercell storm. This storm happened to be NW of Devils Lake, and was intercepted sucessfully with large hail and a rotating wall cloud / funnels. I also decided to go the extra 20 miles to the Canada border before returning to Jamestown, ND for the night as the next day will be a chase day farther south. This day was, put aside hurricane chases, the longest chase ever in my life!

May 28 - Chase day with severe storms intercepted in SW South Dakota. Forecasted in Jamestown, North Dakota to determine today's target area. There were two prospects, one again in northeastern North Dakota (departing surface low) and another in southwestern South Dakota (lee cyclogenesis was a possibility). If the low did not develop SW of South Dakota and the low in NE North Dakota did not move, northeastern South Dakota would have been good for possible storms. I left Jamestown and targeted Aberdeen, South Dakota. Here is where I waited for quite a while, watching the SE winds there quickly go SW as a cold front surged past Pierre to my west. Meanwhile, agitated cumulus appeared on the visible satellite in both NE North Dakota and SW South Dakota, nothing in my area. After another hour or so, the cumulus to the SW kepts building, and was in far better upper-air dynamics, plus slowly backing winds, despite it being in the post-frontal air. There was a very strong cap, and that helf off anything in ND (although an isolated cell fired there). I decided to go with SW SD so I headed southwest to Pierre, then targeted Kadoka, South Dakota. Storms were building rapidly to the southwest, and finally, a violent storm (hail and high winds) was intercepted near Wanblee in the Pine Ridge Indian reservation. After intercepting the storm, it was then a long drive through severe weather along Interstate 90 until west of Kennebec, where it cleared. The night was spent in Chamberlain, South Dakota as the next days chase prospects are SE Nebraska / NE Kansas.

May 29 - Today was supposed to be a chase day farther southeast (NE Kansas / SE Nebraska) but a cold front surged ahead of all the good upper air dynamics, so a long travel day (but trying to play along the front) from Chamberlain, South Dakota down into northeastern Kansas through southeastern Nebraska, then southwest into Liberal in SW Kansas anticipating a good setup for storms on 5-30. Managed to document some dust devils in eastern Nebraska, convection along the stalled cold front in NE Kansas, as well as very interesting dryline induced convection farther in SW Kansas. Also stopped in Hallam, Nebraska along the way to check out how the town was doing after a tornado destroyed it 2 years prior on May 22, 2004. I was delighted to see most of the town rebuilt. Met up with Verne Carlson and Tony Laubach in Liberal to share a room for the night.

May 30 - Chase day in western Oklahoma area. Forecasted and left Liberal, Kansas targeting development southwest of Woordward, Oklahoma. This was a dryline type setup with an outflow boundary and stationary front to play with. An upper air disturbance passed over the target region with an increase in upper winds in the right-rear entrance region of the jet stream flow. The storm was a supercell storm that was followed down and west of Highway 283 from near Cheyenne, Oklahoma to Interstate 40 until it gusted out violently.

May 31 - Departure and travel day. No storms were intercepted today or were in range. Returned the rental vehicle and left Oklahoma City, OK to return to Fort Lauderdale, FL.


1). May 18,4:00 PM - Penetration of strong thunderstorms along Interstate 70 just west of Brazil, Indiana. The storms were high-based but produced very heavy rains, small hail, 40-MPH winds, and occasional lightning. The storms developed in a region of strong northwest flow aloft on the backside of a departing upper-level low pressure system. Surface heating and an upper level trough triggered the storms. Documentation was HD video (time lapse) and still images. A 2007 Ford Focus was used to chase the storms.

2). May 21,4:30 PM - Interception of a very severe thunderstorm on the east side of Springfield, Missouri near Interstate 44 and Highway 65. The storm was a classic to LP type supercell storm, which lasted about an hour but dissipated rapidly after moving south of a boundary it developed on. The storm produced heavy rains, 40-MPH winds, and hail to 3/4". Strong rotation was noted with the storm, with some small funnels, an RFD notch, and beautiful "stacked plate" effect on the storm updraft. A low pressure trough, surface boundary interactions / fronts, surface heating, and mesoscale low-pressure area caused the storms. Documentation was HD video and digital stills. A 2007 Ford Focus was used to chase the storm.

3). May 21,4:30 PM - Penetration and observation of a strong thunderstorm near Plad, Missouri along highway 64. The storm was the western most part of a multicell cluster of strong thunderstorms. The storm produced heavy rains, 30-MPH winds, and hail to 1/2". A low pressure trough, surface boundary interactions / fronts, surface heating, and mesoscale low-pressure area caused the storms. Documentation was HD video and digital stills. A 2007 Ford Focus was used to chase the storm.

4). May 22,6:30 PM - Observation of a strong thunderstorm in far northeastern Colorado near the tri-state regions of Colorado, Kansas, and Nebraska along highway 45 / 385. The strong thunderstorm was high based, but developed a weak precipitation core and had very weak rotation before falling apart. The core of the storm was not intercepted. An area of surface convergence, upper trough, upslope orographics, and surface heating produced the storms. Documentation was HD video and digital still photos. A 2007 Ford Focus was used to chase the storm. A severe thunderstorm watch was also in effect for the area until 10 PM CDT.

5). May 23,5:00 PM - Penetration of severe thunderstorms and obervation of strong gustnadoes along their gust fronts from near Letcher, South Dakota southeastward as far as western Iowa. The storms were a multicell line of strong and severe thunderstorms and contained wind gusts to 70-MPH with frequent lightning, small hail, and heavy rains. The gustnadoes developed ahead of the line of storms and a few became quite strong (damage observed was tree damage). A low pressure trough (surface and aloft) and surface heating produced the storms. Documentation was HD video and digital stills. A 2007 Ford Focus was used to chase the storms. A tornado watch was also in effect for the area until 9 PM CDT.

6). May 24,7:30 PM - Observation and indirect penetration of a severe thunderstorm near Rock Falls, Illinois along Highway 52 and farther southeast towards Amboy, Illinois. The storm was a small supercell storm that developed at the southern extent of a multicell line of storms. The storm contained lightning, heavy rains, small hail, and wind near 40-MPH where it was penetrated (through a split in the storm). The storm produced quarter-sized hail but the hail core was not deeply penetrated in this storm. A low pressure trough (surface and aloft), cold front, and surface heating produced the storms. Documentation was HD video and digital stills. A 2007 Ford Focus was used to chase the storms. A tornado watch was also in effect for the area until 8 PM CDT.

7). May 25,4:30 PM - Observation a very severe thunderstorm near Elletsville, Indiana near Highway 46. This storm was a small but briefly intense supercell storm with a wall cloud and small funnels produced. Tornado sirens were sounded for the city of Elletsville. The core of the storm was not penetrated, but 40 MPH inflow winds were observed. The storm quickly merged with other storms and formed a multicell squall line. A low pressure trough (surface and aloft), cold front, and surface heating produced the storms. Documentation was HD video and digital stills. A 2007 Ford Focus was used to chase the storms. A tornado watch was also in effect for the area until 10 PM CDT.

8). May 25,7:00 PM - Observation and indirect penetration of a severe thunderstorm north of Spiceland, Indiana north of Interstate 70. The storm was part of a multicell line of strong and severe storms. The storm contained lightning, heavy rains, small hail, and wind near 40-MPH where it was penetrated. A low pressure trough (surface and aloft), cold front, and surface heating produced the storms. Documentation was HD video and digital stills. A 2007 Ford Focus was used to chase the storms. A tornado watch was also in effect for the area until 10 PM CDT.

9). May 27,9:30 AM - Penetration of strong thunderstorms along Interstate 29 south of Omaha, Nebraska just east of the Iowa / Nebraska border in Iowa. The storms were encountered while traveling north, and were elevated multicell cluster type storms. Heavy rains, lightning, and 40-MPH winds were encountered. A upper low pressure trough and left-over convection / outflow boundaries due to an overnight MCS produced the storms. Documentation was digital stills. A 2007 Ford Focus was used to chase the storms.

10). May 27,8:00 PM - Observation and penetration of a very severe thunderstorm in Towner County, North Dakota near Cando along and near Highway 231. The storm was a high-based supercell storm that organized into a tornado-warned (radar indicated) HP supercell storm. The storm had winds over 60-MPH, frequent lightning, heavy rains, and large hail to 1" (quarter sized), although reports of 3" came from nearby (this size was not encountered). A large rotating wall cloud was also observed with this storm, but only some small funnels were produced. A low pressure trough (surface and aloft), stationary front, and surface heating produced the storms. Documentation was HD video and digital stills. A 2007 Ford Focus was used to chase the storms. A tornado watch was also in effect for the area until 12 AM CDT.

11). May 28,9:30 PM - Observation and penetration of an extremely severe thunderstorm near Wanblee, South Dakota in Jackson County in the Pine Springs Indian reservation near highway 44 and Highway 73. The storm was an HP supercell type storm that was on the northern end of a powerful bow-segment in a cluster of severe thunderstorms. This storm had an impressive visual appearance with inflow banding and "stacked plates" appearance on the north "rotating head" cell with a multi-tiered shelf cloud extending southward along the bow segment. The storm did have a wall cloud and rotation, and a tornado warning (radar indicated) was issued for the storm between Wanblee and Long Valley. As the storm approached, 60 to 70-MPH outflow was observed. Conditions in the precipitation core were torrential rains, nearly continuous and frequent lightning, golfball-sizd hail, and winds near 70-MPH. The tornado was not observed since I backed away from penetrating the storm core. Power was knocked out in the town of Wanblee. This storm traveled to the northeast and became a multicell cluster and still produced hail to quarter sized with 65-MPH winds, which was again encountered northeast near Okaton and Murdo along Interstate 90. Power was out also in several towns along Intertstate 90 and a semi-trailer was nearly blown off the road. The storms were caused by an upper trough / jet stream exit region, surface heating of a post-frontal air mass, and developing surface low pressure. Documentation was HD video, audio, and digital stills. A 2007 Ford Focus was used to chase the storms. A severe thunderstorm watch was also in effect for the area until 1 AM CDT.

12). May 30,6:30 PM - Obervation and indirect penetration of an extremely severe thunderstorm from west of Cheyenne, Oklahoma southward along and west of Highway 283 to Interstate 40. This storm had confirmed softball-sized hail, ofcourse that portion of the storm was avoided, abeit close. Upon penetrating the fringes of the storm core, hail to the size ping-pong balls was observed, with torrential rains, frequent lightning with close hits, and 65 to 70-MPH winds. The storm also produced several funnel clouds and had a rotating wall cloud for some time. When the storm gusted out, winds well over 75-MPH were onserved just north of Interstate 40. Tree and sign damage along with flooding ocurred with this storm. The storms were caused by an upper trough / jet stream entrance region, surface heating, dryline, and stationary front / outflow boundaries. Documentation was HD video and digital stills. A 2007 Ford Focus was used to chase the storms. A severe thunderstorm watch was also in effect for the area until 10 PM CDT.

This concludes the Midwestern United States Chase Log for the first trip in May 2006. The summary includes a total of 8 severe thunderstorms, 4 strong thunderstorms, and 2 tornadoes / funnel clouds. The main chase vehicle conducting all chases was a 2007 Ford Focus rental. This information was prepared exclusively for the National Weather service and the team of Skywarn storm spotters.


Chase 2006 Highlights Video


A sunset over western Missouri can be seen while traveling from Oklahoma City, OK to St Louis, MO along I-44. Storms did not develop in these areas, except for the high clouds in this picture, produced from the western edge of a low pressure area aloft.


Here is a picture of Saint Louis, Missouri taken from the Illinois side of the Mississippi River showing the 630 foot high Arch Monument. This day had no storms expected and time was spent in the city checking a possible job opportunity there and shopping for food / supplies. This day, however, did become an unexpected chase day as far east as central Indiana by evening.
Thank God for WiFi! Here is the Weathertap Radar screen when stopped for data off Interstate 70 in west-central Indiana. An upper-level low pressure area is causing storms to erupt in afternoon heating despite cool surface temperatures, NW winds, and low dewpoints.
Here is a developing region of enhanced cumulus (although its base is rather high) in Central Indiana off Interstate 70. These clouds eventually grew into low-topped thunderstorms.
The developing storms in Central Indiana had small but stout rain free bases. The one here has scud rising up into it. Interesting to see this develop in a true cold-core environment.
In this picture you can see a hail shaft (center) associated with one of the cold-core storms. Hail to pea sized was produced by the storm in this picture. The NW flow aloft and at ground level causes convection despite 60 degree surface temperatures because the freezing level is low (only 10,000 feet or so) and yeilds steep lapse rates.
A small funnel, called a cold-air (or cold-core) funnel, slowly turns on the rear flank of an updraft developing north of Interstate 70 in central Indiana near Brazil. The view is to the north. These are generally weak, like the one in the center of this picture.
Cold-core storms often weaken quickly, and the cell peters out and weakens with a glaciated anvil southeast of Brazil, Indiana. Note that the convective cell is both high based and low topped. The view is due south.


Not much in the way of storms again, but looking better with each model run, so today was spent poking around Chicago's Lakefront Drive to pass more "down time". I took the picture above while driving northwards towards Navy Pier on Lakeshore Drive of the downtown Chicago skyline.


Here is a picture of Altocumulus Castellanus (ACCAS) clouds over southwestern Missouri as a region of upper lift moves over the area. This indicates instability aloft, but there is a cap (temperature inversion) below this feature, so surface based convection (storms) never developed. Note the clearer air to the lower-left (looking SW) as the edge of a 500 mb thermal ridge aloft erodes the cloud deck due to sinking air (subsidence).
This is a picture of virga (precipitation aloft) falling from elevated showers in western Missouri. This type of convection and associated precipitation is above the surface and also above any capping inversion, hence the term "elevated". Sometimes you can see sporadic and small flashes of cloud to cloud lightning in these clouds.


This is a picture of linear low clouds along a pre-existing surface boundary between air with different temperatures and / or wind speeds / directions. These boundaries serve as a "forcing" mechanism to initiate thunderstorms. The boundary here (view is to the west) helped trigger supercell thunderstorms near Springfield, Missouri on this chase day.
This is a view of a supercell storm at initiation phase (just developing as cap is being overcome). The view is to the south and the cell is being approached from the north. Nice rain-free base developed and note the RFD notch (clear area in the cloud base) to the lower-right.
The view is now looking to the north from south of the developing supercell over Springfield, Missouri. Rock-hard and tilted convection is rooted in the boundary layer with a "beaver's tail" feature developing (lower center to lower right).
Coming around to the east side of the supercell storm. The view is to the west, and the "round" appearance of the developing mesocyclone becomes apparent in the dark cloud base. Hail up to 3/4" inch was also falling to the east and northeast of the mesocyclone.
Here is a view of the supercell in classic and mature mode. The storm is small overall but rotating without a doubt. Note the striations, as well as the inflow band feature to the right.
Looking nearly straight up into the vault region of the mature storm, we can see impressive striations on the updraft tower. The supercell storm is not rotating hard in the mid-levels. This is called a "barber pole" due to the stripes (striations).
The supercell storm, in the last few pictures, instantly falls apart as the boundary it was "sitting" on moves north. Another strong to severe storm with hail developed on that same boundary and had impressive growth on its westernmost portion as seen in this picture.


Here is a picture of my rental vehicle with the "Weatherlab" weather station mounted on the roof of the vehicle while stopped along the Colorado / Nebraska border east of Wray, Colorado on highway 34.
This picture shows storms initiating in the forecasted target area southeast of Wrey, Colorado. Enhanced cumulus develops and becomes towering cumulus (TCU) which precludes rapid thunderstorm development. The cap here is broken due to upslope forcing (orographics) of southeast winds in upward terrain (about 4,000 feet).
This is all that became of the rapidly developing showers and thunderstorms. In this picture, a weakly rotating cloud base can be seen (an LP supercell wanna-be?) in the center of the picture with a round rain-free base. A small "RFD slot" type feature can also be seen to the lower-left side of the rain-free base. Limited moisture and weak shear caused the storm to fall apart.
Looking upward, with my weather station in the foreground, a weak elevated mesocyclone produces an interesting cloud structure overhead.


A shear funnel appears in a developing cumulus cloud as initiation occurs south of Interstate 90 near Chamberlain, South Dakota. These funnels aloft are caused by directional wind shear in convective clouds.
Here is a picture of a group of storm chasers near Storla, South Dakota. The storms did not go supercellular, as winds aloft were parallel to the moisture axis, so an intense squall line of thunderstorms was produced.
This is a picture of a strong gustnado developing along the gust front ahead of an intense squall line near Letcher, South Dakota. These are tornado like rotations that develop along opposing wind axes (in this case, strong and warm SE winds meeting cooler W winds).
Here is another picture of another gustnado near Letcher, South Dakota.
A bowing out line segment south of Fedora, South Dakota produces a very impressive shelf cloud along the gust front of the severe thunderstorm line. The view is to the south, and this storm had wind gusts near 70-MPH.


Here is a picture of convective initiation southeast of Davenport / Moline, Illinois as the cap is broken in a highly sheared environment. The cell here is on the southern end of a multicell line of storms, called a "Tail End Charley" and has the best chance to acquire supercell characteristics.
A nice flanking line develops on the developing thunderstorm southeast of Moline, Illinois as chasers watch and hope the storm will continue intensifying.
In this picture, about 10-15 minutes later and still southeast of Moline, Illinois, the storm slightly rotates as it becomes a small supercell storm. The weak RFD can be seen in the lower center of the picture and mild striations in the upper right.
In this picture, the same storm reaches Rock Falls, Illinois, and we are now looking southward towards a split in two weak supercells. The original storm we looked at earlier near Moline is to the left and a new supercell storm is to the right. A "hole" develops between the two because one storm is moving east and the southern one is moving southeast and parting from the original storm. Large hail is to the left.
The left split (original supercell) storm becomes loaded with hail making for a greenish-white color to the precipitation shaft. Note the rainbow and interesting subsidence hole punched in the supercell base. This is actually a sign the storm is becoming outflow dominant and developing a shelf cloud.
Passing between the two storms, this picture is the view to the north at the intense hail core and what is left of the mesocyclone noticeable in the center-right of the picture.
Here is another picture of the same storm southeast of Amboy, Illinois as it is nearly entirely outflow dominant and undercutting the southern split storm with outflow winds as storm chasers watch. The old (undercut) mesocyclone is still visible since the weak RFD notch can still be seen just to the right of the tree in the cloud base.
In this picture, the storms weaken into a squall line and evolve into an MCS. All that is left ahead of the storms is a strong gust front and shelf cloud.


Strong and severe thunderstorms begin to develop south of Indianapolis, Indiana in the late afternoon. The storm here is a severe thunderstorm that rapidly developed about 20 miles east of Bloomington, Indiana. The storm did not stay isolated very long, and storms eventually evolved into a multicell line.
A supercell storm, prompting a tornado warning for Elletsville, Indiana, appears over wooded terrain before weakening and becoming entrained into a line of thunderstorms. Note the inflow band to the right, updraft, and if you look closely near the base of the storm, small funnel cloud near the center of the picture.
Here is a picture of a strong gust front and its associated shelf cloud looking north of Spiceland, Indiana.
This is a picture of the backside of the shelf cloud of severe thunderstorms near Spiceland, Indiana. The boiling appearance of the clouds (sheared by outflow air meeting air ahead of the storm system) is sometimes called the "whale's mouth".


This is a picture of Kansas City (on the Missouri / Kansas border) taken from Interstate 70 on the Kansas side while on a long road trip back west anticipating more activity. This was a travel day and no storms were intercepted (actually storms way out in W Kansas and too far out of range were "missed").


Here is a picture of some interesting cloud formations (turbulent "whales mouth" type clouds) associated with a cluster of elevated strong and severe thunderstorms near Omaha, Nebraska while headed north on Interstate 29 from Kansas City, Kansas to Fargo, North Dakota.
This chase day was my first time in North Dakota and beyond! In this picture, I am crossing the state line from South Dakota into North Dakota on Interstate 29 (originating in Kansas City, Kansas) making this the longest chase to this date!
After a long drive north and west of Fargo, North Dakota, a releiving sight of convective initiation can be seen well to the north of Jamestown, North Dakota. This means the capping inversion has been broken, and storms have begun to develop.
One updraft becomes particularly strong, as in this picture, still about 80 miles away from the storm, and acquires supercell characteristics. This supercell is the same storm that will be later intercepted in Towner County, ND northwest of Devils Lake.
Here is a picture of the supercell storm northwest of Devils Lake, North Dakota evolving from a high-based storm to a lower-based storm (lower LCL as higher dewpoints advect towards the storm). Note the lowering developing to the right and drier air "slot" to the left.
Looking north towards the developing supercell storm over Towner County (NW of Devils Lake), North Dakota, the storm takes on a "round" appearance with a developing wall cloud (far lower-left) and inflow "beavers tail" (lower-right). At this point, the storm has a mid-level mesocyclone.
Here is a picture of the "business end" of the supercell storm over Towner County, North Dakota. This is a rotating wall cloud, and the feature lowering to the right is also rotating. Any funnels that formed did not touch down, but the storm was tornado warned as a strong mesocyclone was present (radar-indicated).
This is a picture of the updraft-downdraft interface, or UDI, of the supercell storm just north of the mesocyclone and wall cloud. Precipitation (mostly large hail) wraps around the storm (view here is to the NW) and hail is largest just to the right in this picture. The storm here produced hail up to 3 inches (baseball sized)!
Here is a time exposure picture of some vivid cloud-to-cloud lightning with the storm chase vehicle to the lower left side of the frame.
How far north can you chase? Well, in this picture, this is about it ... I am standing about 100 feet from Canada! In this picture, after chasing storms in northeastern North Dakota, I decided to go an extra 20 miles to the USA / Canadian border, and take this picture of the chase vehicle and myself. Another note about this far north, the sun in late May sets extremely late, and I took this picture at about 10 PM (still cloudy, but in dusk light).


Here is a picture of the first sign of severe thunderstorms from about 50 to 75 miles away. The cirrus / anvil clouds here are storms east of Rapid City, South Dakota viewed from Pierre, South Dakota. The storms to be intercepted are developing and somewhere under the clouds to the far left. The view is to the west-southwest.
This is a picture of a developing supercell storm encountered near Wanblee, South Dakota. The storm is the "rotating head" on the north side of an intense bow echo segment. The chase vehicle and equipment (not wind vane with winds blowing INTO the storm) is to the lower-left.
Looking southward from the supercell, a tiered shelf cloud marks the leading edge of an intense gust front associated with a bow segment where a portion of a thunderstorm cluster punches out due to an intense downdraft.
Similar shot, but without the chase vehicle and equipment, of the northern end of the bow echo with rotating HP supercell, illuminated by lightning in a dusk time-exposure. Impressive inflow bands can be seen to the lower-right. The view is west-northwest.
Behind the gust front it gets too dark for normal photography since it is dusk. In this picture, a digitally processed time exposure, the eerie green glow of hail makes its appearance between the clouds. Lots of scud, and a subsidence (downdraft) hole in the cloud base (slightly left of center of image). The view is northwest.
Looking southward past Wanblee, South Dakota, also in a digitally processed image, the mesocyclone (wall cloud) prompting the radar-indicated tornado warning for this storm can be seen. No confirmed tornadoes touched down but the storms produced golfball-sized hail (note the green tint). Also notice that there are no lights in town functioning (left of water tower).
After being pelted with car-dinging golfball-sized hail and 70-MPH winds as the storm core passed, the hail in this picture lightens up a bit but is still nickel-sized. The supercell storm (weak mesocyclone) continued rapidly northeast.


Here is a picture of one of several dust devils observed behind the cold front in warm, dry air in eastern Nebraska.
Here is a view of downtown Hallam, Nebraska, a small town in southeastern Nebraska that was destroyed by a 2.5 mile-wide (yes, two and a half miles wide) tornado in May of 2004. Two years later, rebuilding of the town is underway. In this picture, two new houses appear with a concrete slab from a destroyed home in the foreground. Only a few trees remained after the tornado, and the pavement in the foreground is fresh (the tornado actually scoured some of the pavement away)!
A rock-hard cumulonimbus tower pops up in northeastern Kansas along the stalled cold front. The storms here were of non-severe / marginally severe pulse type where an updraft grows rapidly then peters out quickly since upper winds are light.
This is a picture of one of many small LP mini-supercell type storms forming along the dryline in southwestern Kansas. Little precipitation came out of these clouds, but note the clear "slot" in the bell-shaped base of the storm (lower center-left part of image).


Convective initiation begins with afternoon surface heating along a stalled boundary ahead of the dryline in western Oklahoma. The storm is just developing and will soon become a supercell thunderstorm.
About a half hour later, the storm is now explosively developing. The view is to the south, and the anvil is blowing off with the jet stream winds from right to left. The supercell updraft and flanking line can be seen from the center of the image and to the right.
A small, slowly rotating funnel cloud develops in the intense rain-free base on the southwest side of the supercell in classic mode. Several funnels were produced by this storm, but none touched down.
Here is a closer view of another of several funnels / rotating wall clouds produced by the supercell when in classic mode. The view is west.
In this picture, the WX Works screen on Verne Carlson's and Tony Laubach's laptop shows a "flying eagle" type radar image, with the visual appearance of the updraft base and wall cloud out the passenger window!
Here is another picture of chasers and their equipment documenting the superell storm as it produces a wall cloud.
Here is a picture of a rotating lowering (wall cloud or large funnel) from within the so called "Bear's Cage" of the storm between the RFD and FFD regions. This is a very dangerous place to view the storm, so we did not stay in this area very long. The only way out is to go southeast and out the "opening" in the supercell notch to avoid the RFD winds to the SW and large hail in the FFD (forward flank downdraft) region to the NE! Ofcourse, the big danger is when we looked up!
Here is a picture of the nearly side-ways rain / hail and violent winds as the supercell storm gusts out violently north of Interstate 40 near Highway 283. Winds here are gusting well over 75-MPH and a branch just fell from the tree in the center of the picture.


This is a picture of a line of storms associated with an MCS between Okalhoma City, OK and Dallas-Fort Worth, TX viewed from an MD-80 at about 21,000 feet on the short connecting trip between the two cities. The pilot did a great job at circumnavigating (going around) the storm cells to avoid the worst of the turbulence. The view out the window was very interesting.

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