656
ACUS03 KWNS 150739
SWODY3
SPC AC 150738

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0238 AM CDT Wed May 15 2024

Valid 171200Z - 181200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM FAR SOUTHEAST
TEXAS INTO MUCH OF LOUISIANA...CENTRAL/SOUTHERN MISSISSIPPI...AND
WESTERN...

...SUMMARY...
Severe thunderstorms are possible from far southeast Texas into much
of Louisiana, central/southern Mississippi, and western Alabama on
Friday.

...East/Southeast TX through the Lower MS Valley and into the TN
Valley/Southeast...
A southern-stream shortwave trough is forecast to extend from
central OK southwestward through Far West TX and into northeast
Mexico early Friday morning. A belt of moderate to strong
southwesterly flow aloft will likely extend through the base of this
shortwave, from northeast Mexico through east/southeast TX and the
Lower MS Valley into the TN Valley/Southeast. This belt of stronger
flow will persist throughout much of the day as its parent shortwave
trough shifts eastward/northeastward.

The surface pattern is a bit more uncertain, with the progression of
an early morning MCS potentially influencing conditions
significantly. General expectation is for moderate to strong
buoyancy to develop during the afternoon and evening, ahead of the
weak front associated with the approaching shortwave trough. Strong
vertical shear will be in place as well, supporting the potential
for organized storms, including supercells. Upscale growth into a
convective line is possible as well. Highest probability for severe
currently appears to be from far southeast TX across much of LA and
central/southern MS into western AL. Some severe potential could
extend farther north into the TN Valley, but uncertainty regarding
moisture return and the track of the surface low precludes
introducing anything higher the Marginal/5% severe probabilities
with this outlook.

...Northern Plains into the Upper MS Valley...
A northern-stream shortwave trough is forecast to move through the
northern Rockies on Friday, reaching the northern High Plains by
early Saturday morning. An attendant surface low will move eastward
just ahead of the shortwave, moving across southern Saskatchewan and
Manitoba. Surface lee troughing will sharpen ahead of the shortwave
trough as well, with cyclogenesis anticipated across western SD. A
few high-based thunderstorms may develop along the cold front
connecting these two surface low. Strong outflow is possible within
these storms, although low coverage and limited magnitude precludes
introducing any severe probabilities with this forecast.

..Mosier.. 05/15/2024

$$