Skip Talbot
EF5
Interesting setup across portions of the northern plains/northern MS river region. NAM and GFS seem to be in fairly good agreement about advecting mid 60's dewpoints into eastern NE/SD/southern MN by Tuesday evening leading to moderate instability beneath a 40-50 knot south/southwest low level jet and 30-50 knots of southwest midlevel flow. Weak capping and the lift from the well established flow aloft should lead to ongoing convection and storms across Minnesota. These storms may intensify later in the day. I'm a little more interested in eastern SD/NE where initiation should be delayed until the arrival of stronger flow aloft later in the afternoon. Storms should initiate along a weakly capped dryline by mid to late afternoon. The dryline looks a little sloppy, but is forecast to remain mostly stationary. High based storms over veered surface winds should be able to push off the dryline into richer air where the winds are better backed by evening. I'd expect storms to mature then and with 40 knots of effective shear and pockets of effective srh over 200, supercells and a few tornadoes look possible. Given the sloppy surface features, surface winds and low level jet that could be more backed, and weak upper level flow, there's probably going to be a mix of storm modes including lines, clusters, and supercells that have a tendency to go HP. I'm hoping for a tail end charlie play that is able to remain inflow dominant as it pushes off the dryline, and then spins up as the low level jet ramps up in the early evening. Watching Sioux Falls, SD right now for the best shot at a semi discrete, photogenic supercell and maybe a tornado, and portions just south of there depending on how far south the line of cells extends, and then into western IA by evening where the line should track. Certainly not an outbreak event or even a tornado producer, but could be a fun and photogenic chase with slow moving supercells, so I'll probably bite on this chase. It's May after all!
