1). April 24, 4:00 PM - Interception of an extremely severe and tornadic thunderstorm near Baird and along Highway 283 and about 5 miles north of Interstate 20 in Callahan County, Texas. The storm was a classic / HP supercell tornadic storm moving northeast from near Abilene, Texas to near Moran. At least two tornadoes were observed with this storm. The first was a stove pipe / elephant trunk tornado observed at close range (less than 1 mile) from along Highway 283. This tornado lasted roughly 5 minutes, and weakened before hitting any roadways. The second tornado was from the left-split of the same supercell as it evolved to HP mode, and was basically a very large rotating mass / wall cloud observed near the intersection of 283 and farm road 576. The tornadoes occurred over open / rural country and did not affect any populated areas. The core of the supercell, with possible hail to 4" (grapefruit sized) was not penetrated, however, 70+ MPH winds (mainly RFD), hail to 1", torrential sheets of rain, and extremely frequent lightning with numerous close hits was encountered. The storm continued northeast towards Moran producing additional funnel clouds. The storms were caused by a stationary front, developing dryline, strong wind shear (strong winds aloft), surface heating, and a low pressure trough (surface low and trough aloft). A 2011 Hyundai Elantra was used to chase4 the storms. Documentation was still digital photos and HD video. A tornado watch was also in effect for the area until 12 AM CDT.

2). April 24, 6:00 PM - Interception of a very severe and tornadic thunderstorm northeast of Abilene and north of Interstate 20 (Clyde) in Callahan County, Texas. The storm was an intense tornadic HP supercell moving northeast from near Abilene and over open country. Another tornado was observed with this storm, with a rapidly rotating wall cloud and later a broad area of rotation with smaller vortices briefly touching the ground on the eastern flank of the storm. The core of the supercell, with at least baseball sized hail (2.5+") was not penetrated. Winds near 65 MPH, hail to 1", heavy rain, and frequent lightning was also observed with this storm. The storms were caused by a stationary front, developing dryline, strong wind shear (strong winds aloft), surface heating, and a low pressure trough (surface low and trough aloft). A 2011 Hyundai Elantra was used to chase4 the storms. Documentation was still digital photos and HD video. A tornado watch was also in effect for the area until 12 AM CDT.

This concludes the Chase Log for the southern US Plains and Midwest tornado chase trip from April 23 through April 25, 2011. The summary includes a total of 2 severe thunderstorms and at least 3 tornadoes. The main chase vehicle conducting all chases was a 2011 Hyundai Elantra. This information was prepared exclusively for the National Weather service and the team of Skywarn storm spotters.

May 20 - This was a travel day with a flight from Fort Lauderdale, FL to Kansas City, MO with a stop-over in Tampa. The arrival into Kansas City was delayed a bit, and after arriving I picked up the rental vehicle and set it up with equipment off the airport. Anticipating an un-determined target the next day, I headed east on Interstate-70 and spent the night in Booneville, MO.

May 21 - May 21 began with forecasting and leaving Booneville, MO early with a primary distant target as Tulsa, OK. The best route to Tulsa was to drop south and southwest on Highways 153 and 54 to Highway 71, then west and southwest on Interstate 44 into Oklahoma. I arrived at Tulsa, OK in time for lunch and looking at data. The SPC had a large slight-risk area, extending from eastern Nebraska and south to central Texas. Wind and hail probabilities were set at 15% and 30% (hatched for hail), respectively. The highest tornado probabilities of 5%, extended from Texas into Oklahoma near Tulsa. It became apparent that there was a lot of capping (convective inhibition) and a very inactive dryline was noted with a line of cumulus well east of Oklahoma City. I headed south out of Tulsa on highway 75, then west along Highway 48 until near I-35 near Wellston. I was ready to call the day a "cap bust" when a distant cell was noted along the dryline to the SE. I headed south quickly through Oklahoma City and caught up with the supercell storm near Sulphur, OK along and near Highway 7. By this time (7 PM or so), the SPC placed tornado watch 320 in the area of south-central OK. The supercell storm produced at least 4 tornadoes! After intercepting the first storm, another storm was noted near Ada while heading along Highway 48, also producing tornadoes, one of which was noted from a distance. The chase was wrapped up by heading northwest on 3W / Highway 177 to Interstate 40, then west into Oklahoma City for the night.

May 22 - Today was a chase day with the interception of an extremely violent tornadic supercell near Joplin, MO. The chase began in Oklahoma City after forecasting a primary target of near the OK / KS / MO borders. I headed up I-44 to Tulsa and checked data there. SPC had a moderate risk outlook in place, with a 10-15% hatched tornado outlook, 15% damaging wind, and a 45% hatched hail for probabilities. By early afternoon, mesoscale discussion #853 and subsequent tornado watch box 325 for the targeted area. Out of Tulsa, I headed north on Highway 169 to intercept a developing storm targeted near Parsons, KS and near and south of Highway 400. I basically followed this supercell storm from initiation near 4 PM and well to the southeast along highways 160 / 69 and then 96 into Missouri and eventually I-44 until it evolved into a line segment. Large hail and the violent winds of the backside of a destructive tornado / RFD were encountered north of Joplin and near Carthage. The chase of this storm was wrapped up near Chesapeake with a return west along Highway 60 and 39 back to I-44 for a brief damage survey near Joplin. I-44 was closed, with trucks and vehicles overturned, as well as EXTREME damage to Joplin (with numerous fatalities). The road closured forced a southward track out of Se Joplin and south along Highway 175 to 60, then west all the way to Bartlesville, OK for the evening.

May 23 - May 23 was a moderate risk chase day with the interception of a very intense supercell in SW Oklahoma. The chase began by leaving Bartlesville, OK after forecasting a primary target area from near Enid southward to Cordell. I headed west on Highway 60 to I-35, then south to Highway 64 and west to Enid. After easting and looking at more data, it became apparent that SW Oklahoma (near I-40 and Highway 183) would be the best place for discrete supercells. I headed out of Enid via Highway 60 and 18, south through Watonga, then SW on Highway 33 to Highway 183. Meanwhile, the storm prediction center had a moderate risk outlook, with a 10% tornado, 15% wind, and 45% hatched hail probabilities. Mesoscale discussion #896 and subsequent tornado watch box 345 was also issued for this target area. The first storms were encountered near the intersection of Highway 33 and 183. Later on, farther south, another supercell with extremely destructive hail was intercepted SE of Cordell near Highways 9, 115, and 9. This supercell produced hail around 6 inches in diameter, setting a new state record hail-size for Oklahoma! The chase was wrapped up after hail damaged the vehicle (including a cracked windshield). I headed east on Highway 62, then north on Highway 81 to I-40, then back into Oklahoma City for the night.

May 24 - Today was a high risk chase day, which began with forecasting and leaving Oklahoma City for a primary / tentative target of Enid, OK by heading up Highways 3 and 81. SPC had a high risk for a large portion of Oklahoma, with probabilities denoting a 30% hatched tornado, 30-45% wind, and a 45% hatched hail threat. After lunch, it was determined the best storm chanced / initiation may take place farther southwest in the areas near Highway 183 and I-40. A call was made to head back south on Highway 81 to Kingfisher then west on Highway 33 then south to near Calumet along N2740 to 270, and eventually west to near Weatherford along I-40. During this time, SPC issued Mesoscale Discussion #925 and subsequent PDS (Particularly Dangerous Situation) tornado watch box 356 for the area. Initiation also was taking place in the aforementioned area west of Highway 183. The first cluster of supercells was encountered in the area near Putnam and Arapaho near highways 33 and 270. Attempting to remain ahead of the storms, I opted to take 33 and 270 through Watonga then southeast to near Calumet. A supercell / wall cloud was encountered south of Watonga, then an extremely violent supercell near Calumet, with a rain wrapped tornado in near total darkness passing less than a mile south of me just north of I-40 on 270 (with an audible roar)! The chase then turned east on I-40 with damage observed and a loud roaring sound from a damaged refinery. I headed north again on Banner road out of El Reno and encountered the damage path north of Hefner road. This tornado was entirely rain wrapped. I then reached highway 3 and headed southeast through Piedmont, where more extensive damage was observed. I continued to John Kilpatrick Turnpike to divert north around Oklahoma city, then north on I-35 to reach the same supercell in Guthrie. I bailed on the intercept because the storm had a tornado that was too rain wrapped. I headed back south on I-35 to I-40 east, intercepting another supercell near Tinker AFB and noted debris (including sheet metal) falling from the sky! I headed south on Sooner road and to the I-240 exit for a fuel stop, but the tornadic storm there became outflow dominant. I headed east on I-240 then I-40 where I ran into Bill Hark and intercepted a very impressive stovepipe / rope tornado just northwest of Shawnee. This tornado mangled a semi-trailer and injured the driver, so I stopped to assist. After, I continued back west on I-40, then to I-35 and I-44 to stay again in Oklahoma City for the night.

May 25 - Today was a very "long-shot" chase day with a long drive to the high-risk area in eastern Missouri from Oklahoma, and ultimately catching numerous severe storms and at least one tornado. After a quick forecast, I left Oklahoma City at about 8:30 AM and headed up I-44 making Tulsa, OK by about 10:30 AM. More forecasting on the road revealed a target area 50 to 100 miles to the south and east of Saint Louis, MO. Meanwhile, SPC had a large high-risk area, with 30% hatched tornado, 30% wind, and 45% hatched hail probabilities. I continued northeast along I-44, with a quick diversion at about 11:30 AM into Joplin to survey some of the May 22 devastation there. While continuing NE through a developing severe storm near Springfield, SPC posted mesoscale discussion #952 and subsequent tornado watch boxes 369 and PDS (particularly dangerous situation) 370 including my target area. Clusters of severe storms and supercells began developing from east-central MO to the eastern portion of the state. The first tornado-warned supercell was encountered near Rolla, MO. The chase continued to the NE along I-44 to Cuba, MO then south on Highway 19 through Steelville with another HP supercell storm encountered. I headed east on Highway 8 through Potosi to near Desloge and south on Highway 67. The first significant supercell of the day was encountered north of Fredricktown, MO and a brief tornado was observed with this storm. Some tree damage was noted in Fredricktown. I headed east on Highway 72, encountering two more severe storms near Patton and Millersville. I finished the chase by heading north on I-55 near Cape Girardeau and spend the night in Saint Louis, MO.

May 26 - May 26 was an off day with a long reposition back to Oklahoma after spending the night in Saint Louis, MO. I was able to see the Gateway Arch tram as well as the extremely high water of the Mississippi River during the morning. I left Saint Louis and stopped for lunch near Creve Coure and then headed back to I-44 for the long trip back to Oklahoma City. I stopped again in Joplin, MO to take more footage of the devastation, as well as donate some food and water I didn't need. I arrived back in Oklahoma City at about 9:30 PM, anticipating a possible chase day near that area the next day (May 27).

May 27 - Today was a very marginal chase day, but ended up as a classic "cap bust". I forecasted and left Oklahoma City around lunch time, initially choosing the area from near I-35 to Enid (shear axis and instability seemed good there). I headed up I-35 to Perry for lunch. SPC had a small area of slight risk from NE Oklahoma and southwest to SW Oklahoma. Tornado probabilities were set at only 2%, with a 15% hail and 5% wind probability. As the day went on, it appeared the area of interest would be farther southwest to near I-40 and west of Oklahoma City due to very high CAPE (instability) in that area. I headed west on Highway 164 out of Perry and south on Highway 81, then west on 51 to Okeene to check data. SPC issued Mesoscale Discussion #997 for the area in SW Oklahoma, with a weak surface low and dryline present - Albeit no clouds. I creeped south a bit on Highway 8 to Watonga and waited there for a few hours. The dryline / low remained inactive due to the very strong capping inversion. Some cumulus developed to my north, so I headed back up Highway 8 in that direction. The cap was still too strong, and the convection dissipated near Hitchcock just before sunset. I was aware a "cap bust" was in progress, and got nothing but a suntan. I ended the day by heading northeast to Canton, then west on Highway 51 to Highway 270 (then 183) towards Woodward. I was stopped by law enforcement near Mutual for speeding down a hill (75 in 65) and had my car searched (I was told of a BIG problem with meth in that area), but the friendly officer let me off with a verbal warning. I continued to Woodward, then north on Highway 183, then highway 34 to 400 and into Dodge City for the night. And, as luck would have it, I was pulled over AGAIN, this time for failing to turn signal pulling into the motel - And AGAIN, like before - The friendly officer just warned me verbally and gave me directions to the motel! At least I should be in a good position for May 28's slight risk in the high plains?

May 28 - Today was another highly conditional chase day with low hopes ending up with a bust in NE Colorado. I forecasted and found two areas, one in Missouri and the other in NE Colorado, the latter being a half days drive and easily reachable. SPC had a slight risk extending from NE Colorado, across N Kansas, and into Missouri towards Illinois. The tornado probabilities ranged from a measly 2% in NE Colorado to 5% in Missouri, along with 5% wind and 15% hail probabilities. Upslope flow and lee cyclogenesis were encouraging factors in choosing NE Colorado as the target. All in all, no good storms developed in either regions (Colorado nor Missouri). The eastern regions remained capped, and the Colorado target was trumped by cool temperatures and lack of moisture return. I left Dodge City, KS and headed west into Colorado on Highways 50 then north on 287 out of Lamar. I then took Highway 40 west and northwest to near I-70 near Limon, then west on I-70 to Byers. I waited for some time and it seemed like clouds were not getting very organized, despite a strong Denver Cyclone / DCVZ in the afternoon. I hung out anywhere east of Denver International airport in open country near Highway 79 (Bennett and Prospect Valley) and only light showers developed with cool temperatures. Once again, a long drive ended up empty handed. I headed west on I-70, spending the night in the east side of Denver near Aurora.

May 29 - May 29 involved a very long drive to get into position for more activity farther east for the last couple of days of chasing for this trip. In addition to a long drive from Denver, Colorado to SE Nebraska / NE Kansas, a marginal setup existed for severe weather in the target area, with a slight risk issued by the SPC, with a 2% tornado, a 5% damaging wind, and 15% hail probability. I forecasted and found the best place to be in early evening was SE Nebraska / NE Kansas with a potential dryline / warm front interaction there, along with decent upper-air support. I left Denver, CO rather early, heading out on I-76, then I-80 into Nebraska all the way east until near York. I then headed south on Highway 81, while trying to troubleshoot some frustrating data issues. I saw a cell firing in NE Kansas south of Beloit, about 75 miles to my SW, so I continued down Highway 81 to Highway 9 out of Concordia, then west towards Glenn Elder and Highway 24. SPC also issued Mesoscale Discussion #1018 and subsequent severe thunderstorm watch box 396. I headed south on Highway 181, intercepting a nice LP supercell northwest of Tipton. After the intercept, I headed back north on Tipton Road to Highway 24, then north on Highway 181 / 78 into Kansas to Highway 4, then east to Highway 81, then north into York, NE for the night.

May 30 - This was the last chase day of this trip, and was a moderate risk chase day in north-central Nebraska. With morning forecasting in York, NE it appeared the setup was such that initial storms would produce tornadoes, but then transition quickly into a squall line / derecho by evening. The SPC had a moderate risk out for the area in north-central Nebraska stretching into SE South Dakota. Initially, the tornado probabilities were set at 15% hatched, but later dropped to 10% (not hatched) on the 1630z outlook. The hail and wind probabilities were kept at 30% hatched and 45% hatched, respectively. I left York and headed north on Highway 81 into Norfolk, then west on Highway 275 to Oniel, waiting on more data and finalizing the target areas for initiation, which now appeared to be more towards north central Nebraska instead of far SE South Dakota. There was also quite a number of other storm chasers congregating in Oniel. The SPC then issued Mesoscale Discussion #1029 and subsequent tornado watch box 402 for the area. Storm initiation began southwest of Oniel by about 3:30 PM, and a chase track west on Highway 275 to near Bassett, then south on Highway 183 was executed. The cold front was encountered near Bassett, so a trip south on 183 was necessary for a large severe storm northeast of Brewster. This storm was encountered, and caused extensive damage to the chase vehicle (windshield smashed and numerous dents from baseball hail). A developing tornado was observed with this storm. Additional storms also developed as the evolution to a squall line commenced. I hung around Highway 183 near Rose, meeting up with many other chasers, including Scott Mc Partland, Bill Hark, Mark Robinson, and others. The chase continued south after that, I tool Highway 96 to Burwell then west on Highway 91 to continue back south on Highway 183. I bailed going south on another intense storm near Ansley, and got off 183 and took Highway 2 all the way to Grand Island, then south on Highway 281 to Highway 36 east, then continued south on Highway 81 into Kansas and to near I-70, spending the last night in Salina.

May 31 - This was the travel and departure day. I packed up early in Salina and arranged insurance paperwork for the damage to the rental vehicle, which was returned in Kansas City. I Flew out of Kansas City International back to Fort Lauderdale, Florida (connecting in Chicago, Illinois). This concludes this exciting (and tragic) chase trip in 2011. Total mileage on the vehicle was about 5934 miles.

1). May 21, 7:30 PM - Interception and observation of an extremely severe and tornadic thunderstorm in Murray and Ponotoc Counties, OK and northeast of Sulphur along Highways 7 and 1. The storm was a classic tornadic supercell thunderstorm, with a very impressive structure. At least 4 tornadoes were observed with this storm, ranging from rope to small stovepipe and eventually multi-vortex. The storm core, with hail to baseball sized, was not penetrated. No damage was found because the tornadoes affected very remote / rural areas. Other conditions encountered were winds gusting near 70-MPH (mainly RFD), heavy rains, occasional lightning, and some hail to golfball-sized. The storm was caused by a low pressure trough, wind shear (strong winds aloft changing direction with height), surface heating, and a dryline boundary ahead of a weak low pressure system. A 2010 Nissan Versa was used to chase the storm. Documentation was HD video and digital still pictures. A tornado watch was also in effect for the area until 12 AM CDT.

2). May 21, 9:30 PM - Observation of another extremely severe and tornadic thunderstorm northwest of Ada in Ponotoc County, OK from near Highway 377. The storm was mainly observed from a distance (20 miles or so) with a very impressive storm structure (striated and tilted updraft). Closer to the storm, a large cone tornado was observed on the rear-flank side of the supercell from southeast of Ada, at a distance of about 10 miles in twilight. North of Ada, hail to 2" was observed on the edge of the storm core, causing the chase to be aborted and leaving two dents in the top of the vehicle. Other conditions observed were frequent lightning (the core was not directly penetrated) and 35 MPH winds. The storm was caused by a low pressure trough, wind shear (strong winds aloft changing direction with height), surface heating, and a dryline boundary ahead of a weak low pressure system. A 2010 Nissan Versa was used to chase the storm. Documentation was HD video and digital still pictures. A tornado watch was also in effect for the area until 12 AM CDT.

3). May 22, 6:00 PM - Penetration and observation of an extremely violent and tornadic thunderstorm from near Parsons, Kansas in Labette County near Highways 59 and 160 and well to the southeast through Jasper County north of Joplin along Highway 96 and eastward along Interstate 44 through Chesapeake. This storm was a long track and violent HP supercell storm. The core of the storm was indirectly penetrated southeast of Parsons, KS and hail to golfball sized was observed. The core had hail up to grapefruit sized. The same storm split and the right split became extremely intense, causing a violent (EF-5) tornado to affect Joplin, Missouri. The tornado was not directly observed, as the storm was approached from the backside, but the circulation was viewed briefly when it was west of Joplin. Debris was noted falling from the sky with 70+ MPH winds, golfball sized hail, and torrential rains with frequent lightning. Damage in Joplin was very severe, including a destroyed hospital, numerous vehicles overturned, and many fatalities (at least 160 people killed). The storm was caused by a low pressure system, surface heating, a dryline boundary, and very strong wind shear in the atmosphere / jet stream aloft. A 2010 Nissan Versa was used to chase the storms. Documentation was HD video and digital still pictures. A tornado watch was also in effect for the area until 9 PM CDT.

4). May 23, 3:30 PM - Observation of a developing severe thunderstorm near the intersection of Highway 183 and Highway 33 north of Arapaho in Custer County, Oklahoma. The storm was an LP supercell storm and some funnel clouds (one ropelike and nearly a third way to the ground). Frequent lightning with a couple of close hits was also observed, but the storm core was not penetrated. The storm merged with a line of storms, so it was abandoned for more discrete supercells to the south (although this storm did eventually wind up producing a couple of small tornadoes). The storm was caused by a low pressure trough, wind shear, surface heating, and a dryline boundary ahead of a weak low pressure system. A 2010 Nissan Versa was used to chase the storm. Documentation was HD video and digital still pictures. A tornado watch was also in effect for the area until 10 PM CDT.

5). May 23, 6:00 PM - Observation and indirect penetration of an extremely severe thunderstorm east of Highway 183 and near Highways 9 and 115 in Washita County, Oklahoma and near and southeast of the town of Gotebo. The storm was a classic supercell storm, with an extremely striking visual (stacked-plates) appearance. Hail up to 4" was observed with this storm, despite INDIRECTLY penetrating its core, which had hail even larger (the storm produced hail around 6 inches in diameter, and was confirmed as a new state record hail-size for Oklahoma)! The storm also had frequent lightning with close hits, inflow winds measured at least 40 MPH, heavy rains, and stronger winds in the core. A funnel cloud was also observed on the SW side of the supercell updraft. The storm later weakened near Carnegie and became outflow dominant. Hail damage was the most obvious affects of this storm, and my vehicle was not an exception (numerous roof dents and a cracked windshield from near baseball sized hail falling from the storm anvil). The storm was caused by a low pressure trough, wind shear, surface heating, and a dryline boundary ahead of a weak low pressure system. A 2010 Nissan Versa was used to chase the storm. Documentation was HD video and digital still pictures. A tornado watch was also in effect for the area until 10 PM CDT.

6). May 24, 4:00 PM - Interception and observation of a very severe, and possibly tornadic thunderstorm southwest of Watonga, Oklahoma in Blaine County from near Highway 270. The storm was an HP supercell storm, with a large rotating wall cloud on its southern side. Some small funnels were noted before the storm was abandoned for a more intense one farther south. The core of this storm, containing hail to baseball sized, was not directly penetrated. Conditions encountered were 40 MPH winds, heavy rains, frequent lightning, and hail up to nickel sized. The storm was caused by a strong low pressure system, strong upper trough, speed / directional wind shear, dryline, and surface heating. A 2010 Nissan Versa was used to chase the storm. Documentation was HD video and digital still pictures. A PDS tornado watch was also in effect for the area until 10 PM CDT.

7). May 24, 5:00 PM - Interception and penetration of an extremely severe and violent tornadic thunderstorm south of Calumet, Oklahoma in Canadian County from near Highway 270 and I-40 and points well east and northeast to near I-35 and John Kilpatrick Turnpike and south of Guthrie. The storm was a violent HP supercell storm, which produced a large and destructive long-track rain-wrapped tornado. This tornado was also rated EF-5, with a mile-wide damage path, and a track-length of about 75 miles. At least 9 People were killed by this tornado. The conditions near Calumet included isolated hail up to 2" (or larger), extremely frequent lightning with numerous close hits, torrential rains, and winds gusting over 75 MPH. The storm was extremely dark, and a large rain wrapped wedge tornado was encountered about 1 mile north of I-40 on highway 270. I had to back off and let it pass, after being able to hear the roar from it. This rain wrapped tornado and storm was chased from near this location on and off via various road options until south of Guthrie. Damage was extensive in some areas, along a southwest to northeast path. A loud jet-engine sound of the tornado was noted on I-40 just east of Highway 270 at a distance of 1-2 miles. Other damage was to trees, fences, signs, and severe structural damage to buildings and homes (including roofs torn off and some completely destroyed). The storm was abandoned south of Guthrie because it was rain wrapped and too dangerous to chase. The storm was caused by a strong low pressure system, strong upper trough, speed / directional wind shear, dryline, and surface heating. A 2010 Nissan Versa was used to chase the storm. Documentation was HD video and digital still pictures. A PDS tornado watch was also in effect for the area until 10 PM CDT.

8). May 24, 6:00 PM - Interception and indirect penetration of a very severe and tornadic thunderstorm southwest near and south of Tinker AFB in Oklahoma County from near Sooner road and I-240. The storm was a violent classic (evolving to HP) supercell storm which produced a tornado that damaged buildings near Moore, OK. At my location near the SE side of the Air Force base, extremely frequent lightning with many close hits, heavy rains, 50 MPH winds, and hail to golfball sized was encountered. Debris was also noted falling from the sky, including large pieces of sheet metal! The storm eventually became outflow dominant. The storm was caused by a strong low pressure system, strong upper trough, speed / directional wind shear, dryline, and surface heating. A 2010 Nissan Versa was used to chase the storm. Documentation was HD video and digital still pictures. A PDS tornado watch was also in effect for the area until 10 PM CDT.

9). May 24, 7:00 PM - Interception and penetration of another very severe and tornadic thunderstorm northwest of Shawnee, Oklahoma along I-40 and near S Harrah road overpass. The storm core had a brief period of 40 MPH winds, nickel sized hail, heavy rains, and occasional lightning. A wall cloud was noted on the south side of the storm, moving rapidly NE. Before the gust front from the previous weakening storm near Tinker AFB had a chance to undercut this supercell, it produced a small but very intense tornado. The tornado quickly formed and lasted about 5 minutes, crossing I-40 and tossed / ripping apart a large semi-trailer (driver was injured but alert as I had to stop and help). Another couple driving was also nearly hit, and one member had to lie in a ditch. Other than tree and sign damage, this tornado was in a rural area. The storm was caused by a strong low pressure system, strong upper trough, speed / directional wind shear, dryline, and surface heating. A 2010 Nissan Versa was used to chase the storm. Documentation was HD video and digital still pictures. A PDS tornado watch was also in effect for the area until 10 PM CDT.

10). May 25, 2:30 PM - Penetration of a strong to severe thunderstorm near Springfield, Missouri in Greene County along I-44. The storm was a portion of a line of strong and severe storms. Conditions encountered with this storm were 40 MPH winds, heavy rain, occasional lightning, and hail up to dime sized. Conditions causing the storms were surface heating, an low pressure trough, wind shear, and a strong upper level low. A 2010 Nissan Versa was used to chase the storm. Documentation was digital stills and HD video. A tornado watch was also valid for the area until 6 PM CDT.

11). May 25, 4:00 PM - Interception and observation of a severe and possibly tornadic thunderstorm near Rolla, Missouri just south of I-44 in Phelps County. The storm was a small HP supercell storm, and a rotating wall cloud with funnels passed over Rolla, with the tornado sirens blaring. Conditions encountered with this storm were 40 MPH winds, heavy rain, occasional lightning, and hail up to dime sized. Conditions causing the storms were surface heating, an low pressure trough, wind shear, and a strong upper level low. A 2010 Nissan Versa was used to chase the storm. Documentation was digital stills and HD video. A tornado watch was also valid for the area until 6 PM CDT.

12). May 25, 4:30 PM - Interception and penetration of a severe and possibly tornadic thunderstorm south of Cuba and north of Steelville along Highway 19 in Crawford County, Missouri. The storm was another small HP supercell storm. Conditions encountered when penetrating this storm were 50 to 60 MPH winds, heavy rain, occasional lightning, and hail up to nickel sized. A rotating wall cloud with small funnels was noted on the updraft side of this storm. Conditions causing the storms were surface heating, an low pressure trough, wind shear, and a strong upper level low. A 2010 Nissan Versa was used to chase the storm. Documentation was digital stills and HD video. A tornado watch was also valid for the area until 6 PM CDT.

13). May 25, 5:30 PM - Interception and penetration of a very severe and tornadic thunderstorm near Fredricktown in Madison County, Missouri near Highways 67 and 72. The storm was a classic supercell and a brief tornado was observed on the southern side of the storm, with a rapidly rotating wall cloud. The tornado caused some tree damage, as well as minor damage to a gas station. Conditions encountered when penetrating the core of this storm were 50 to 60 MPH winds, torrential rain, frequent lightning, and hail up to golfball sized. A rotating wall cloud with small funnels was noted on the updraft side of this storm. Conditions causing the storms were surface heating, an low pressure trough, wind shear, and a strong upper level low. A 2010 Nissan Versa was used to chase the storm. Documentation was digital stills and HD video. A PDS tornado watch was also valid for the area until 9 PM CDT.

14). May 25, 4:30 PM - Interception and penetration of a severe and possibly tornadic thunderstorm in Bollinger County, Missouri along Highway 72 west of Patton. The storm was a small HP supercell storm. Conditions encountered when penetrating this storm were 50 MPH winds, heavy rain, frequent lightning with some close hits, and hail up to nickel sized. A rotating wall cloud with small funnels was noted on the updraft side of this storm. Conditions causing the storms were surface heating, an low pressure trough, wind shear, and a strong upper level low. A 2010 Nissan Versa was used to chase the storm. Documentation was digital stills and HD video. A PDS tornado watch was also valid for the area until 9 PM CDT.

15). May 25, 4:30 PM - Interception and penetration of a severe thunderstorm near Cape Girardeau, Missouri along Highway 72 west I-55. The storm was an intense multicell storm, with winds gusting over 65-MPH, torrential rains, nickel sized hail, and frequent lightning with some close hits. Conditions causing the storms were surface heating, an low pressure trough, wind shear, and a strong upper level low. A 2010 Nissan Versa was used to chase the storm. Documentation was digital stills and HD video. A PDS tornado watch was also valid for the area until 9 PM CDT.

16). May 29, 7:00 PM - Interception and observation of a very severe thunderstorm near Tipton, Kansas in Mitchell County near Highway 128. The storm was a classic / LP supercell storm, with a rather high base but impressive visual appearance. The core of the storm was barely penetrated, and hail up to 2" in diameter was measured with the storm passage. The storm also contained occasional lightning, 30 MPH inflow winds, and heavy rains. Conditions causing the storms were surface heating, an upper trough, weak low pressure, and warm front / dryline interactions. Documentation was digital stills and HD video. A 2010 Nissan Versa was used to chase the storm. A severe thunderstorm watch was also in effect for the area until 11 PM CDT.

17). May 30, 4:00 PM - Observation and penetration of an extremely severe and tornadic thunderstorm north of Rose, Nebraska along Highway 183 in Rock County. The storm was a very intense HP supercell storm, undergoing transition into a strong bow segment, but still capable of producing tornadoes. A large funnel and wall cloud / tornado was observed in an inflow "notch" of this storm, just before the intense precipitation core slammed the vehicle. Conditions encountered in this storm were 70+ MPH winds, frequent lightning with some close hits, torrential rains, and hail at LEAST baseball sized (3") falling nearly horizontally. The hail shattered the windshield and severely dented all metal on the vehicle, even breaking a windshield wiper and plastic faring below it. Fortunately, the storm remained over mainly remote areas in the Nebraska "Sandhills" region. Conditions causing the storms were a cold front, strong upper trough, and surface heating. Documentation was digital stills and HD video. A 2010 Nissan Versa was used to chase the storm. A severe thunderstorm watch was also in effect for the area until 9 PM CDT.

18). May 30, 5:00 PM - Interception and observation of a very severe thunderstorm near Rose, Nebraska along Highway 183 in Rock County. This storm was another tornado-warned HP supercell that moved over nearly the same area affected by the previous storm. The storm was undercut by outflow, but did have a striated presentation visually as well as a well-defined hail core (green sky)! I did not penetrate the storm core, which had hail to at least 2". Conditions encountered were 60 MPH winds, small hail, heavy rains, and frequent lightning. Conditions causing the storms were a cold front, strong upper trough, and surface heating. Documentation was digital stills and HD video. A 2010 Nissan Versa was used to chase the storm. A severe thunderstorm watch was also in effect for the area until 9 PM CDT.

19). May 30, 7:00 PM - Interception and penetration of another very severe thunderstorm near Ansley, Nebraska along Highway 183 and Highway 2 in Sherman County and many points east and southeast to south of Grand Island, NE in Hamilton County and Highway 281. The storm was a serial derecho (multicell cluster / line of thunderstorms) containing hail up to quarter sized, winds gusting over 80 MPH, torrential rains, and frequent lightning with close hits. The storm caused tree and building damage, as well as knocking out power to many towns. Large gustnadoes were also observed on the leading edge of the gust front. Documentation was digital stills and HD video. A 2010 Nissan Versa was used to chase the storm. A severe thunderstorm watch was also in effect for the area until 9 PM CDT.

This concludes the Midwestern United States Chase Log. The summary includes a total of 19 severe thunderstorms and about 12 tornadoes (or large funnel clouds). The main chase vehicle conducting all chases was a 2010 Nissan Versa. States chased or visited during this trip were CO, KS, IL, MO, NE, and OK. This information was prepared exclusively for the National Weather service and the team of Skywarn storm spotters.