ACUS01 KWNS 211624
SPC AC 211622
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1022 AM CST Thu Feb 21 2019
Valid 211630Z - 221200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
Widely scattered thunderstorms are possible across much of the Deep
South today and tonight. Isolated thunderstorms may also affect
parts of Arizona and southern California today.
...Deep South including East Texas to the Carolinas...
A consolidating front will move slowly north/northwest through
tonight toward the TX coastal plain, across southern portions of
LA/MS, and across south-central AL. Showers and widely scattered
thunderstorms are expected north of this front with warm/moist
advection focused atop the sloping frontal zone. A sporadic instance
of marginally severe hail cannot be conclusively ruled out across a
broad corridor with MUCAPE exceeding 1000 J/kg in some cases;
however, the overall potential for sustained/organized severe storms
will likely remain low.
Any prospects for near-surface-based convection will be confined to
the immediate frontal corridor across southeast LA and far southern
MS into south-central portions of AL/GA. While a conditionally
supportive environment for a few strong/locally severe storms may
materialize in this corridor this afternoon/early evening, the
likelihood of near-boundary or warm sector convection will be
limited by persistent cloud cover and weak forcing influences within
the warm sector amidst gradually rising upper heights.
An increasingly low latitude upper trough will continue to
amplify/dig southeastward over the Southwest Deserts toward Baja
California and other parts of northwest Mexico. Related DCVA and the
left-exit region of a cyclonically curved upper jet will coincide
with steep lapse rates for the possibility of a few thunderstorms
across southern California as well as parts of AZ.