Potential upgrade mentioned in the latest SPC update for 3/17
Further east across northeast LA into MS and AL a more concerning
scenario appears possible. Most forecast guidance agrees that a
round of afternoon thunderstorms are expected. This activity is
expected to develop in weaker ascent, driven by heating and low
level warm advection. Strong 0-3 km shear near 30-40 kt will already
be in place with enlarged low level hodographs evident. Given weaker
forcing, this activity will have an opportunity to remain more
discrete and any cell will quickly become a supercell capable of
producing strong tornadoes. As a 40-50 kt low level jet increases
around 00-03z, intense supercells are expected to advance eastward
along with the cold front across MS and into AL overnight. This will
bring a second round of significant severe storms capable of intense
tornadoes, large hail and intense damaging winds across much of
MS/AL. If these trends are maintained, an upgrade to a High risk
could be necessary with the initial Day 1 Convective Outlook at 06z
tonight.