- Day Three
acus03 kwns 200715
Storm Prediction Center ac 200714
Day 3 convective outlook
National Weather Service Storm Prediction Center Norman OK
0214 am CDT Fri Apr 20 2018
Valid 221200z - 231200z
..there is a marginal risk of severe thunderstorms from southern
Alabama/southeast la eastward through the Florida Panhandle...
Isolated severe thunderstorms are possible across portions of the
southeast states and Florida Panhandle.
An upper low will continue eastward through the lower MS valley and
into the southeast states on Sunday. A weak surface low will move
eastward/southeastward just ahead of this upper low, likely tracking
generally southeastward along a warm front. By 12z Monday, this
surface low is expected to be centered over southeast al, with a
cold front extending southward into the Gulf of Mexico and a warm
front extending southeastward into the Florida Big Bend.
..eastern la into Florida Panhandle/Big Bend...
Modest destabilization is anticipated within the warm sector ahead
of the surface low. More robust destabilization will be tempered by
widespread cloudiness but continued moisture advection will likely
result in dewpoints in the low to mid 60s and MLCAPE around 500
j/kg. The position of the warm front has varied within the guidance
over the last few runs and the current expectation is for the front
to extend from near mei southeastward to near aaf at 21z Sunday.
Despite modest instability, strong shear supports the potential for
a few organized storms along and south of the warm front during the
afternoon. A more developed convective line is possible over the
north-central Gulf as the cold front moves through the area. This
line could impact the Florida Big Bend very late in the period. Marginal
severe probability (i.E. 5%) has been introduced across these areas.
Uncertainty and generally modest severe potential preclude higher
probabilities with this outlook.