THIRTEEN TORNADOES OBSERVED AROUND CENTERVILLE, SD
Chase Account by: Scott Blair
Chase Team: Scott Blair, Eric Nguyen
7:00pm. We observed a developing supercell after crossing into South Dakota on Hwy19 near Vermillion. A large wall cloud developed and persisted. Shortly after, a long tail cloud developed and the storm showed clear signs of intense rotation. The rotation became violent after heading north out of Meckling towards the storm. It was obvious the supercell was close to producing a tornado.
Tornado #1 / 7:33pm-7:36pm. First tornado of the day rapidly touched down about a mile north of our location. It contained multiple tubes rotating around a central axis. Several of these tubes touched down. This was a very dramatic sight to start the day.
7:41pm. After the first tornado lifted, rotation continued to tighten. We decided to reposition and blasted east and then north on Hwy46. We observed numerous funnels, but none appeared to touch down. We stopped about 1/2 mile away from the lowering and watched with good contrast.
Tornado #2 / 7:46pm-7:57pm. A strong tornado developed around 7:46pm. A nice funnel protruded from the middle of a large wall cloud. The tornado developed and immediately became stronger. The cone continued to grow with numerous multiple vortices spinning around the circulation. The width of the tornadic circulation could be estimated as large as a 1/3 mile wide. The tornado moved generally west, nearing the town of Centerville, SD. Many power flashes were observed as several vortices caused damage.
Tornado #3 / 7:56pm-8:00pm. The third tornado developed a couple miles east of the ongoing tornado #2. At the birth, two tornadoes were on the ground. Tornado #2 dissipated and tornado #3 strengthened. Debris was noted with the white cone as the tornado slowly moved west. Towards the end of its life, the tornado vertically roped out before tilting upward and dissipating.
Tornado #4 / 8:00pm-8:02pm. As tornado #3 began to rope out, a new meso rapidly developed just west of the ongoing tornado. Again, two tornadoes were on the ground briefly until tornado #3 lifted. Tornado #4 was a thin cone tornado lasting just over two minutes. We decided to reposition right as tornado #4 formed. The tornado later dissipated as we drove north on Hwy19.
Tornado #5 / 8:05pm-8:08pm. We continued north on Hwy19 to gain better contrast. After a few minutes from the previous tornado, a new large bowl shaped tornado developed just NNW of our location. The tornado was multi-vortex and appeared to inflict little damage besides lofted dirt. After a few minutes, the tornado lifted and the debris ceased. At 8:11pm heading north, we were stopped by debris from the previous tornado #3. A weak structure and power poles were splintered across the road. Almost immediately, several chasers jumped out and moved debris out of the road. Eric and I helped after I called NWS OAX to report the damage and forward the report to NWS FSD. It was excellent to see the teamwork of everyone, which helped free the road for emergency workers.
Tornado #6 / 8:13pm-8:16pm. Immediately after the debris was cleared from the road, a new tornado rapidly touched down just WNW of our location. We moved up the road about a 1/2 mile and pulled over. The tornado had a smooth laminar appearance. Numerous satellite funnels rotated around the tornado. The tube was multiple vortex as debris rotated around.
Tornado #7 / 8:19pm-8:23pm. A new meso developed directly west of the previous tornado. Rotation rapidly increased and a small debris cloud followed. After dust whirls on the ground, a more intense funnel developed inside the overall circulation. A needle tornado persisted for a few minutes before dissipating into a wild turbulent tube aloft.
Tornado #8 / 8:28pm-8:38pm. Tornado #8 morphed into many physical changes while on the ground for at least ten minutes. A large funnel lowered virtually to the ground with numerous thin multi-vortex tubes rotating around. The tornado then developed into a bowl shape with small vortices continuing. Eventually tornado #9 formed to the east and it appeared tornado #8 was affected with some ingesting taking place. After tornado #9 dissipated, the tornado quickly grew in strength and size. It turned into a stovepipe appearance before becoming rain wrapped and losing visibility.
Tornado #9 / 8:30pm-8:35pm. Tornado #9 developed about 1.5 miles east-northeast of the ongoing tornado #8. A small funnel was first observed before rapidly developing into a stretched condensation tube touching the ground. The tornado immediately kicked up debris and continued to increase its angle. Both tornadoes were on the ground and it appeared they had influence on each other. Eventually, tornado #9 intensified and became more vertical. The tornado moved due east. During the dissipating stage, the tornado had rapid motion with wild split vortices inside the main condensation tube.
Photos of Tornadoes #10 - #13 will be posted at a later date.
Tornado #10 / 8:54pm-8:59pm. After repositioning due to a pointless roadblock, we drove due west towards the storm. A smooth funnel was soon observed as it developed into a tornado. Light was tough to come by with sunset past. Tornado did minor damage.
Tornado #11 / 9:00pm-9:01pm. As soon as tornado #10 lifted, another tornado developed with the old meso north of Lennox. It appeared to quickly become rain-wrapped and lifted shortly after. Tornado #12 / 9:29pm-9:33pm. After shifting more northwestward, a weak tornado was observed while driving. It appeared to produce little to no damage. Tornado #13 / 9:45pm-9:49pm. Last tornado of the day as we stopped to video/shoot the supercell. A large funnel was persistant with debris noted at times when lightning would backlight.
KFSD- Ending the day. The chase finally ended shooting stills near FSD. Monster meso became entrained into major squall line as it approached our area. End result was a breathtaking show as the complex moved into FSD.