Looking at what data we have so far for Monday, convection will complicate things north of I80 in the Ohio Valley/Midwest, and there will be a stubborn capping inversion south of I40 across the Tennessee Valley. I don't necessarily think the early-day activity in northern Missouri into central Illinois will totally wash out the threat there northward, but it will make the situation more complex. Likely that it will set up some boundaries that storms can take advantage of later. Highest unconditional threat may end up being during the late evening hours across Arkansas and the vicinity of the Missouri Bootheel, moving into parts of Tennessee and northern Mississippi overnight. In the Southeast, models have been pretty consistent in maintaining a wedge that's blocking any meaningful surface-based thermodynamics from taking hold more or less east of I65. Weak high pressure located off the coast seems to be reinforcing it as well. While it's impossible to know how accurately the models are depicting this, if there's anything I know, it's to never bet against a wedge. I think this system could be real trouble anywhere west of the wedge, however.
Things have really slowed down on the speed of additional convection after our first round, with things kind of stalling out over the course of Tuesday. NAM suggests a second round of storms late Tuesday night into Wednesday morning, and is still persistent with the idea of secondary low development. This looks to significantly enhance kinematics, with widespread swaths of SRH exceeding 250 m2/s2 across Mississippi, Alabama, Tennessee and Georgia. It also really breaks down the wedge, ushering in dews of 60-65 degrees. While we'll have to see how things trend, it certainly seems like
Tuesday into Wednesday morning could be a sneaky but substantial severe weather threat for the Southeast, with storms capable of all hazards. Either way, it's pretty clear that the next 48 hours will be pretty active across a wide swath of the continental US.
