SLGT risk of Severe Weather today/3-18...Extreme heat continues across much of the USA...Snowy in the Southwest

Spotty Severe Weather tonight and tomorrow

Spotty Severe Weather seems likely overnight and into tomorrow as a potent upper level low moves across Iowa, Minnesota, and Michigan tomorrow. At this time, a batch of heavy rainfall with occasional embedded severe thunderstorms is moving across southeastern Arkansas and eastern Louisiana, where Tornado Watch #72 is in effect until 200 AM CDT. While isolated spin-up tornadoes, large hail, and damaging wind gusts are possible, especially due to strong wind shear and favorable wind profiles across the region, instability seems too meager to support a more significant threat of severe thunderstorms. As the night progresses, expect this line of storms to gradually die out.

For the day tomorrow, the Storm Prediction Center (SPC) has issued a Slight risk of Severe Weather across northeastern Illinois into much of lower Michigan. As daytime heating occurs across this area, expect little in the way of convective inhibition by the afternoon hours. Despite model differences between the GFS and NAM, strong forcing ahead of a trailing cold front should allow for severe thunderstorms capable of producing large hail, damaging wind gusts, and isolated tornadoes. Farther to the south across Kentucky, Tennessee, Alabama, and Mississippi, convective initiation ahead of a stalling cold front may occur. However, due to dry air and lack of significant forcing, the main threat will likely be large hail.

Storm Prediction Center Day 2 Probabilistic Outlook