LIVE MAP (ABOVE) ... SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1125 PM CST Wed Dec 28 2022
Valid 291200Z - 301200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF
EAST TEXAS...WESTERN LOUISIANA...SOUTHERN ARKANSAS...
...SUMMARY...
Isolated severe thunderstorms are possible this afternoon into
tonight from east Texas and western Louisiana northward into
southern and central Arkansas. Locally damaging wind, isolated hail,
and a brief tornado or two are all possible.
...Synopsis...
A mid/upper-level shortwave trough is forecast to move from the
southern High Plains this morning into parts of the Midwest/Great
Lakes by the end of the forecast period. A weakening cold front is
expected to move slowly eastward across parts of the
central/southern Plains, as a frontal wave moves from KS toward the
upper Midwest. Relatively rich low-level moisture will continue to
stream northward into the ArkLaTex region through the day, in
advance of the cold front.
...ArkLaTex and vicinity...
Showers and isolated thunderstorms will be possible this morning
from southeast TX into LA and southern AR, as low-level moisture
continues to deepen across the region. More substantial thunderstorm
development is possible by late afternoon into the evening across
parts of east TX, as modest diurnal heating/destabilization (with
MLCAPE potentially increasing to 1000+ J/kg) occurs in the vicinity
of the cold front. Moderate southwesterly midlevel flow along the
southern periphery of the departing midlevel shortwave trough will
support effective shear of 35-45 kt, sufficient for organized storm
structures.
Initial semi-discrete development could pose a hail risk within 1-2
hours of initiation, in addition to a threat of isolated damaging
wind. Generally unidirectional wind profiles will favor a quick
transition to more of a linear or QLCS mode as storms move from east
TX into parts of AR/LA tonight, with increasing low-level flow/shear
supporting a continued threat of isolated damaging gusts, and
perhaps a brief tornado or two. Convection may tend to weaken as it
moves into an increasingly stable environment across eastern AR and
northeast LA overnight, but storms may remain vigorous near or just
offshore of the Gulf Coast through the end of the forecast period.
..Dean/Grams.. 12/29/2022
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