Today will be a pretty active day across the South, especially in a corridor along and south of I-20 from Louisiana into Mississippi. Tornadoes will be possible, with some strong tornadoes even a possibility. Hail and damaging winds are on the lower end of threats today, but if a line can form overnight, at least a slight risk of damaging winds will exist.
Aloft, a 500mb jet streak will move east and begin to nudge into the South into the afternoon. The increasing lift from this feature will result in scattered/widespread storm development from East Texas into Louisiana no later than the noon hour.
Just off the surface, 850mb winds will be quite strong all day, but they ramp up considerably after dark. This will act to enlarge hodographs and create an environment favorable for low-level mesocyclones this evening across the south.
A moist airmass will result in at least weak instability today. Ongoing cloud cover will hamper surface heating somewhat, but there should be enough to get storms up and rotating. Of particular concern is a pretty obvious lifting warm front that will be somewhere on an E/W line across Louisiana this afternoon. This feature will likely enhance storm rotation if a dominant supercell can interact with it.
The famed ‘spinny storms index’ shows increasing potential of rotating storms throughout the afternoon, with the risk peaking at and just after sunset in Louisiana and west Mississippi. This isn’t an overly strong signal, but models struggle to produce robust UH with the type of storms that will produce tornadoes today. In my head, this is a somewhat strong signal we could have a tornado or two this afternoon and tonight.
The Bottom Line
Today is going to feature a lot of storms. So many that storm mode MAY act to limit the threat of tornadoes through much of the day. Still, if robust/dominant supercell modes can get going and persist, especially in the late afternoon and early evening, tornadoes seem pretty likely, with a strong tornado possible.
Low-level shear is strong, and the exceptionally low cloud bases will mean tornadoes will not have much trouble getting going. This type of environment results in pretty wide tornadoes if you get a robust low-level meso. When cloud bases are this low and storms are rooted this close to the surface, it doesn’t take that much to get them to produce tornadoes.
I suspect we’ll see a few tornadoes today and a LOT of storms in a giant mess. You must be weather-ready no later than noon if you live in this area. We’ll be all over social media (and maybe even our YouTube channel) discussing today’s storms.