Hey guys thanks! Tornadoes wasn't my first thought when I saw the almost no precipitation and high based nature of the cell I was on. Not to mention the radar appearance was fairly poor - (though 55dbz core seemed to work it's way down the tilts prior to TG). At 8:30 a.m. yesterday I noticed some light/moderate showers extending from NW of Brookings down into SE SD, these would generally clear the area by 10:00am. It occured to me that this was probably a blessing in disguise as it would definately increase helicity and also kept the tempatures back just a bit- thus lowering LCL's (but also making us wait just a tad later for convective temp to be reached). I almost got drawn down to the southern boundary (with unison forecast of helicity and instability max over by Yankton at around 21z and intiation seemed pretty likely with sustained MCONVG) but the pooling of moisture E -NE of the low kept me farther north just long enough to see a couple radar scans which showed cells already merged with each other, no thanks. After another hour, I noticed 17.5dbz at BR3 from FSD radar I took off up I-29 and then went west towards the cell. Coming into visual I just wasn't impressed with it, the updraft was defined and seperated from the rather weak downdraft, but it was high-based, flat and there was little precipitation our outflow winds. As I got just a bit south to where blue sky illuminated the side of the updraft, I could see an incredible anvil and crisp slanted updraft that indicated to me that it was a decent supercell at the time. Then a cone like funnel appeared widend a bit and the surface circulation started. The condensation funnel appeared Cone at first and then more scorpion stinger during it's strongest phase and ended with the expected rope and lifting even though the surface was still launching dirt and such into the air.
Strangely, it was after the tornado lifted that a wall cloud came down and started rotating something ferocious, with fingers coming out pushing outwards towards the ground and then retracting. That lasted a couple minutes and the cell completely and totally fell apart. The same thing happend with the next cell to the north, which for about 30 minutes was an impressive little storm. It had a flanking line with a nice tilted updraft and an area of perfeclty rounded striated clouds at about 10kft- then the top shooting up. That cell looked more mini-sup than anything and had a much lower cloud base than the previous cell. In the instant that cell was no more either.