:: Windy and Wet
Today's 12Z model runs are running in a dead heat...so the forecast certainty is solidifying nicely in the near term period. Last 48 hours has seen an impressive southerly flow set up camp in the region. H70 LLJ with max cores of 60kts have been streaming TX cT and entrance-tapped guld moisture to the upper Mississippi River valley. The cores are deep-running, and surface winds have seen 20-30kt sustained conditions with gusts well over 40-50kts in some areas where downmixing has been most prevalent. Main energy trigger has been long wave trough now running from Great Slave Lake in the NWT to the Four Corners. Progs have this feature digging even further south than originally expected, spelling out a delay of CFP from the associated sfc front now draped across the James River Valley in the Dakotas.
Now (23Z on the 22nd) several instability showers have sprouted in the warm sector dominating the North Star State. TCU's visible on GEOS and out the window all quads here in Lakeville. Deck of StratoCu and Stratus also has built into the mid-level. Due to minor low level capping, along with the swift southerly flow, these are rainmakers, but not much else attm. Progs show some diminished strength in the LLJ core after 00Z, and we should see development curb as a result. However, both models prog the H70 jet to reorganize in earnest, especially after the 06Z window, compelled by rapid mid-level cyclogenesis over srn SK. Secondary LLJ max also progged from NE through IA for strengthening over the same period. Models have somewhat of a different view of "what happens next". NAM has more confidence in morning TSRA and remnants keeping instability at bay through tomorrow, whereas GFS paints a more tame AM and a PM period with more convective potential. 00Z model runs will have to resolve this disagreement, as well as questions of severe potentials. SPC now has us back under the slight risk for tomorrow. Soundings forecast vertical shear along the front as it slowly moves into wrn MN. Hopes are 00Z model will incorporate a better ensemble to either support or deny the threat, as the current 12Z run does not do much more than confirm what we already have - warm humid, windy, and somewhat wet.
I will plan on an update after the 00Z models are accessible....late tonight. Also, a look at the holiday weekend forecast. Short term forecast...Mostly cloudy 40% chance of a stray shower or thunderstorm tonight. Low 56. Tomorrow AM, 50% chance of showers and thunderstorms, mostly cloudy, temps in the 70's.