A RISK FOR SEVERE STORM THURSDAY OVER THE SOUTH

There is a “Slight” risk for severe storms in western/southwestern portions of the area late Thursday and a “Marginal” risk for areas generally along and west of I-55. Damaging winds and tornadoes will be possible. Please continue to check for additional updates.

Convection will be ongoing Thursday morning in a low-level warm advection regime ahead of an approaching upper low/trough and attendant surface front. The southerly low-level flow will allow Gulf moisture to advance northward ahead of the surface front from east TX into MS.

Low to mid-60s F dewpoints will largely remain near/south of the I-20 corridor, with better quality dewpoints remaining closer to the coast. The corridor of relatively higher dewpoints will also become increasingly narrow/pinched off with north and east extent after 00z. Furthermore, forecast soundings show lackluster midlevel lapse rates with eastward extent. This should result in a fairly confined area of elevated instability sufficient to support organized convection amid strong vertical shear. As such, severe potential is expected to decrease with eastward extent during the nighttime hours quickly.

Nevertheless, strong storms are expected to persist along the eastward-advancing surface front through the day across east TX. By late afternoon into early evening, a low-level jet will increase as convection encounters a somewhat more moist boundary layer across LA. This may result in a brief increase in severe potential across portions of LA and adjacent MS when a period of favorable shear overlaps with better instability/quality dew points. Convection will likely remain elevated regardless, but strong to severe gusts are possible, in addition to a few instances of hail.

While poor low-level lapse rates and limited surface-based instability will temper the tornado risk, low-level hodographs will become enlarged and curved with the increasing low-level jet around 00z. If low-level thermodynamics evolve more favorably than forecast guidance suggests, a tornado or two may be possible.