Justin Turcotte
EF5
NAM, GFS, and GEM pretty similar with the potential set-up for Saturday. Some uncertainty as to how Friday night evolves into Sat. LLJ will crank up overnight and convection is likely to develop in ND and spread east. NAM and GEM have a nice H70 shortwave cruising into MN via southwest flow. The GEM is most agressive with developing convection with this feature. NAM and GEM part ways a bit Sat morning but both of them along with the GFS maintain an H70 wave in central MN during the afternoon. CAPE, shear (below H50), and resultant EHI look phenonenal if storms can break the cap/become surface based during the afternoon. NAM is the most bullish on this. Various NWS AFDs are not buying into this scenario by letting the cap win. H70 temps will be hovering between +9 and +12 which is not unbreakable and may actually be preferred as storms would have a better chance of being discreet. The real death cap for MN looks to hold off until Sunday. Flow above H50 is less than ideal so one one need to be an early arrival or hope for backbuilding. Perhaps a 'stealth' tornado set-up which happens up here frequently enough to not ignore the possibility.
Storms are likely to fire in Montana during the afternoon. A few supercells are possible given northeasterly upslope flow with impressive upper level wind field. Storms should congeal into an MCS which would plow through portions of ND during the evening and overnight. Some storms may fire up along the surface boundary snaking across central ND during the afternoon. No shortage of backed low level flow and instability with this boundary. Still a cap here and upper flow is is unimpressive (upper flow now looks a bit better on the 12z NAM)... After all that we'll see what boundaries are sitting around for Sunday.
Storms are likely to fire in Montana during the afternoon. A few supercells are possible given northeasterly upslope flow with impressive upper level wind field. Storms should congeal into an MCS which would plow through portions of ND during the evening and overnight. Some storms may fire up along the surface boundary snaking across central ND during the afternoon. No shortage of backed low level flow and instability with this boundary. Still a cap here and upper flow is is unimpressive (upper flow now looks a bit better on the 12z NAM)... After all that we'll see what boundaries are sitting around for Sunday.