Good morning! I've got to be brief today because I'm already in Missouri and I'm westbound to position for severe weather in the next couple of hours. The target is along the AR/MO border in western MO where I think a low-end tornado threat is coming together. I personally suspect an increase of severe probs from the SPC but we'll see.
So the setup today is very similar to what we saw Thursday (which did produce a brief, but photogenic tornado near Cape Girardeau, MO). It's been yet another tricky forecast with another overnight MCS blasting through the target area during the morning. That said, the atmosphere seems to be recovering well, no doubt aided by deep, tropical moisture, dew points ~70ºF+. Temperatures are in the mid 80's already as well and this has helped increase the degree of destabilization despite convective cloud cover. A semi split-flow jet stream regime is in place and ridging locked in across the area has resulted in strong heating. A speed-max upstream appears to be timed out favorably to cross over southern NO by this evening.
Today's chase really lies in the details though, particularly on the mesoscale. Fairly steep lapse rates (8ºC/km+) associated with the EML are located across OK/KS and as our speed max enters the nose of the southern stream ridge it will spread this plume of steeper lapse rates atop the moist sector, which we already mentioned is very moist and quickly destabilizing.
The real kicker today is the position of a major outflow boundary laid down from the early-period MCS, and other more subtle boundaries as well. Morning surface analysis showed this boundary was located just West of Springfield, MO extending NE/SW. I expect this will serve as the trigger for convective initiation within the next 1-3hrs. Any storms that develop will likely be severe and capable of damaging winds and large hail, given steep lapse rates (low-level and aloft), a well-mixed boundary-layer, and large MUCAPE (4000-5000j/kg) including sufficient CAPE above the -10ºC layer.
Like I said, I think the greatest risk is along and South of I44 to Little Rock, AR. Morning observed soundings showed a strong cap in place but that's been eroding throughout the day due to both cooling aloft and heating below it. A "loaded gun" thermodynamic profile with a somewhat curved hodograph suggests strong rotating updrafts may be supported. Although the tornado threat is low, it's still realistic.
Good luck to others out here today, I think there's one clear target so it should be fun in the jungle.
