Not a particularly easy forecast, and Mike noted the veered 850mb flow (the theme this year, apparently) that may give us issues today. Morning soundings show that the rich moisture has advected northward overnight, with the
FWD sounding showing a ~150 mb deep moist layer. The EML above the returning moist layer is quite impressive, with the
OUN sounding sampling 9.2 C / km 700-500mb lapse rates, including part of a dry-adiabatic layer between 750-550mb. The presence of very steep lapse rates and deep moisture should allow for significant destabilization, excluding possible hindrances of cirrus and top-down moisture depletion caused by dry air advection on the veered flow off the sfc. Speaking of the latter, current profile data from Purcell, OK, show SW flow all the way down to 500m AGL, which is a little concerning to see.
The earlier progs of weak 700mb flow (<20 kts) looks like it won't be as large of an issue, as the latest RUC and NAM progs show >25 kt 700mb flow N of the Red through the evening. In addition, the 12z RUC and NAM runs are forecasting the flow to back behind the dryline by 00z to an easterly direction, which may create convergence problems S of the Red River. Current sfc obs indicate that last night's (00z) NAM run was, predictably, too slow w/ the cold front position this morning; the cold front currently extends along a line from near Lubbock to Childress to Altus to Alva to Salina. Very strong pressure rises (~4.2 mb/3hr) behind the cold front in northwestern OK should ensure that the cold front continues southeastward this morning. That said, as the upper-low continues to approach this afternoon and evening, surface pressure falls in W TX should begin to veer the flow behind the cold front by evening.
I'm still favoring SW through C Oklahoma, particularly since it looks like the triple point is going to be way down near I20 now. Both the RUC and NAM initiate convection from E of Kansas City to San Angelo (and beyond), and a mixed storm mode may dominate given the NNE-SSW orientation of the cold front (w/ 0-6km shear vectors largely to the NE). I'm still not sold on a SE KS target given the NAM consistency in veering the low-level flow ahead of the front up there (though the 12z RUC keeps sfc flow southerly). My thinking is to hang around OUN until early-mid afternoon on the hope that a more specific target will become apparent by that time. The prob of supercells should be relatively greater where the cold front takes a more N-S orientation as such an orientation should allow for a more normal orientation of the deep-layer shear vector to the cold front. FWIW, current sfc obs would argue that would be most in SE KS and adjacent areas of NE OK and SW MO.
