diggin it up
Highly anomalous neg tilt s/w ejecting wednesday afternoon looks poised to provide a damaging wind/tornado threat in IA/MN. Storm motions look to be some of the fastest I've ever seen beneath a 100 knot LLJ, so we're basically in uncharted territory with that. Currently, models show warm sector airmass characterized by upper 50s dews by 00z, but are very aggressive on mixing. Given strength of advection and potential cloud cover, I'm wondering if dews end up closer to 60-61 in reality. That is probably the difference maker between what is a few weak tornadoes and a localized outbreak. Secondly, forcing/ascent is exceptionally strong, so despite good shear vectors off the pacific front, would expect a QLCS in northern portions of the boundary with perhaps a few discrete/semidiscrete supercell structures to exist on the southern flank. An extremely dynamic system is in store and is certainly one that bears watching. I dont know of any good analogs to the parameter space.
As far as the ceiling of this event, concerns I have include aforementioned mixing, whether or not the MLCAPE available is enough to sustain an updraft in that hodograph, and potentially the tendency for mixed/linear modes from forcing.
Secondly, and courtesy of the 100kt 700mb jet, non thunderstorm wind gusts of 60-80mph appear possible across much of Iowa, especially if the models do end up being correct on the degree of mixing.