Chase DetailsSeptember 16, 2006 (Southeast SD/Southwest MN)
Chase Type: Tornado
Chasers: Reed Timmer
Location: Southeast SD/Southwest MN
Distance: 1300 miles
Tornadoes: 3
Max Hail Size: Quarter
Max Wind Speed: 100 mph
Summary
Dave Holder, Matt Chatelain, Trey Perry, Daniel, Curtis, and I chased the previous day in southern Nebraska, largely to be in position for Saturday, September 16 in eastern SD and western MN. After witnessing supercells within incredible shear but insufficient CAPE for tornadoes on Friday, we spent the night in Omaha, NE. The next morning we examined the 12z WRF and RUC forecasts, and decided to head to southeast SD where ~3000 J/kg CAPE, 0 CIN, and good low level shear was forecast. We thought that smoothing errors were present in the 12z WRF forecast of 0-1 km helicity (below right), and the strong 850 mb low-level jet and high helicity values would extend all the way to the boundary in southeast SD. Fortunately, 300+ m2/s2 0-1 km helicity values prevalied over our target area through Saturday afternoon. The 12z WRF forecast CAPE, 850 mb wind, and 0-1 km helicity for 00z Sunday are displayed below.
We drove north on I-29 and decided to head west on I-90 towards Mitchell, SD, after noticing a nice cumulus field north of O'neill, NE. We were having problems with our internet connection, so we called Don for nowcasting, and he informed us that the Sioux Falls, SD radar was down. By this time, we noticed a massive anvil streaming in from our southwest, and Don comfirmed via satellite a storm had initiated to our southwest. Around 3:30 pm, the storm was intercepted and a wall cloud was observed right away. As the storm raced towards our location, the textbook wall cloud began to rotate rapidly, and a tornado warning was issued, I believe around 4 pm. It was very obvious that this storm was going to produce a tornado; it resembled the March 27, 2004 tornado when it developed. As the wall cloud approached us at a high rate of speed, it began to tighten up into a violently rotating bulb, which had a fairly large dust cloud underneath it shortly thereafter. The white rain currents were rotating rapidly around the large bowl funnel. We were only about 1/2 mile north of this developing tornado as it raced northeastward at 45+ mph.
I exited the vehicle as the developing tornado crossed the road about 1/4 mile to our east, and a 80-100 mph westerly RFD wind blasted me from behind as I videotaped the condensation funnel extending to the ground in the field next to us. Just as the funnel was touching down, a heavy rain curtain wrapped around the southwestern side of the tornado and obscured our view temporarily. Thus, we raced to the east and then north and witnessed a fairly intense, white stovepipe crossing the road to our north as we emerged from the hook rain. We continued northward to the west of the tornado and briefly passed into the rain core as we turned east on I-90 to regain a good view of the tornado. By this time, the tornado was just north of the interstate and roping out. The white rope phase was very photogenic, and we saw an overturned semi-truck on I-90 where the tornado crossed.
The second tornado occurred in Minnehaha County and was a nice elephant trunk-shaped tornado with a large dust/debris cloud. This tornado unfortunately destroyed a home, and the people survived the tornado in their basement with no injuries. Shortly after this tornado, we saw a second rope tornado as the supercell crossed into Minnesota. This tornado was just northwest of Pipestone, MN, and passed almost directly over our position. After this tornado, we noticed a weakening trend on radar, and decided to fly southwest after another tornadic supercell taking almost the same path as the first one. However, the supercells to our southwest and west were in a stable, rain-cooled environment, and had little chance of producing tornadoes.
Shown below is the damage survey map from NWS Sioux Falls, SD:
After 40,000+ miles of driving, 2 broken wind shields, and 1 tornado from 30 miles away in 2006, we finally captured a tornado!
We drove north on I-29 and decided to head west on I-90 towards Mitchell, SD, after noticing a nice cumulus field north of O'neill, NE. We were having problems with our internet connection, so we called Don for nowcasting, and he informed us that the Sioux Falls, SD radar was down. By this time, we noticed a massive anvil streaming in from our southwest, and Don comfirmed via satellite a storm had initiated to our southwest. Around 3:30 pm, the storm was intercepted and a wall cloud was observed right away. As the storm raced towards our location, the textbook wall cloud began to rotate rapidly, and a tornado warning was issued, I believe around 4 pm. It was very obvious that this storm was going to produce a tornado; it resembled the March 27, 2004 tornado when it developed. As the wall cloud approached us at a high rate of speed, it began to tighten up into a violently rotating bulb, which had a fairly large dust cloud underneath it shortly thereafter. The white rain currents were rotating rapidly around the large bowl funnel. We were only about 1/2 mile north of this developing tornado as it raced northeastward at 45+ mph.
I exited the vehicle as the developing tornado crossed the road about 1/4 mile to our east, and a 80-100 mph westerly RFD wind blasted me from behind as I videotaped the condensation funnel extending to the ground in the field next to us. Just as the funnel was touching down, a heavy rain curtain wrapped around the southwestern side of the tornado and obscured our view temporarily. Thus, we raced to the east and then north and witnessed a fairly intense, white stovepipe crossing the road to our north as we emerged from the hook rain. We continued northward to the west of the tornado and briefly passed into the rain core as we turned east on I-90 to regain a good view of the tornado. By this time, the tornado was just north of the interstate and roping out. The white rope phase was very photogenic, and we saw an overturned semi-truck on I-90 where the tornado crossed.
The second tornado occurred in Minnehaha County and was a nice elephant trunk-shaped tornado with a large dust/debris cloud. This tornado unfortunately destroyed a home, and the people survived the tornado in their basement with no injuries. Shortly after this tornado, we saw a second rope tornado as the supercell crossed into Minnesota. This tornado was just northwest of Pipestone, MN, and passed almost directly over our position. After this tornado, we noticed a weakening trend on radar, and decided to fly southwest after another tornadic supercell taking almost the same path as the first one. However, the supercells to our southwest and west were in a stable, rain-cooled environment, and had little chance of producing tornadoes.
Shown below is the damage survey map from NWS Sioux Falls, SD:
After 40,000+ miles of driving, 2 broken wind shields, and 1 tornado from 30 miles away in 2006, we finally captured a tornado!
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General Photos
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Highlight Video
WARNING: This may contain language not suitable for children! Be advised!
Tornado video storm chasers supercell
Video of TornadoVideos.net storm chasers intecepting 3 tornadoes over beautful South Dakota farmland. The tornado touched down less than 1/4 mile from the chasers, with 80-100 mph winds in the rear flank downdraft.
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