June 23rd, 2002 Brown County, SD Cyclic Tornadic Supercell
I left Denver with my tour group headed for my target of Aberdeen at 6 AM. Nearly 850 miles later, we arrived. A nice warm front boundary/dryline intersection was very evident on NEXRAD from ABR. We sat there and waited, for a whole 45 minutes for storms to form. Towers went up on the triple point, but could not get into the deep moisture. The west side of the dryline temp and dews were 97/54 with a 240 wind at 20. East of the triple point temp and dews were 91/72 with a 170 wind at 15. North of the warm front temp and dews were 81/77 with a 80 wind at 15. Perfect set up!!! Not to mentions 50 kt 500 mb winds and SBCAPE of 5,500 j/kg. Around 6:30 PM an area of congestus managed to sustain itself south of Forbes, ND, and north of Leola, SD. A storm rapidly developed here. We blasted through the core to be greeted by a long beaver tail being inhaled by the updraft. I have NEVER seen such a beaver tail moving westward at such a rapid motion into the updraft before. It was incredible. The updraft had a low pregnant base with a gorgeous vault visible extending to the northeast. The storm was moving east. At 7:18 PM CDT, a dirt swirl appeared under a rapidly rotating base. By 7:20 PM a rather large tornado developed and crossed county road 23. This tornado had VIOLENT motion at the base and became a large dusty cone. As it moved east the meso took on a large perfectly round barrel shape as the tornado, now a wedge, continued east. At 7:50 PM it dissipated completely as an occlusion was clearly in progress.
At 7:50 PM, the second tornado developed about 2 miles northeast of the first and just northeast of my position. It was a beautiful white elephant trunk with inky black debris cloud. It quickly widened into a large stovepipe with a satellite tornado on its north side. A second satellite tornado developed to its west and roped quickly. We decided to get east of the tornado on highway 10, and to our surprise, it started moved southeast. We drove to the south of it as debris was falling on the vehicle. The tornado was only 200 yards to our north as the outer edges of the debris cloud engulfed our vehicle as we sped east of it. Too close a call for me!!! We stopped a half mile east and shot more video of this now large stovepipe, turning into a wedge. The sun lit the background orange as the black wedge bore down on our position. We headed east on a dirt road stopping to shoot continuous video, only to be chased back in our vehicle to escape. As we drove past a farmhouse a husband and wife were outside watching and waving us to stop and seek shelter.
The tornado, now visions of Pampa 95, bore down on their house. I only hope they made it to the basement in time as the violently rotating tornado headed directly for their house. We continued east and finally stopped for video to watch the tornado dissipate at 8:18 PM. We ran into Gene Rhoden and he quickly pointed out another rapidly developing tornado to the southeast of the previous one, on the ground at 8:23 PM. We dropped south 2 miles and headed east again as a beautiful grey elephant trunk developed with large debris cloud. Another satellite tornado developed on its southern side and lasted for 3 minutes before being swallowed by the now large wedge. This tornado dissipated at 8:36 PM. Finally a large stovepipe developed at 8:36 after another occlusion and was the most photogenic of all. The sun had come out under the barrel, striated updraft and this tornado was being blocked by the setting sun. What an awesome sight!!!!!!! It stayed in place until 8:54 when it finally roped out. All in all, 5 significant tornadoes, 3 satellite tornadoes and a landspout. This storm was one of the prettiest warm front cyclic supercells I have ever seen.
We went back to the NWS office in Aberdeen to share our video with them and to look at the damage survey they did. Clearly the last tornado was F4 or low end F5 (F4 officially) and several other tornadoes were F2 and F3. Fortunately the town of Barnard was spared as there would have undoubtedly been total destruction there. I received some incredible photos from Mr. Gene Olson of Barnard, South Dakota. They are very worth checking out. Click on this link to see them. They are awesome. OLSON TORNADO PHOTOS.
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