SPC AC 281238
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0738 AM CDT Sat Sep 28 2024
Valid 281300Z - 291200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Severe thunderstorms are not expected today.
...Synopsis/Discussion...
The mid/upper-level pattern features mean ridging over the West and
troughing in the East. The pattern is anchored by a large, nearly
stacked cyclone -- resulting from the combination of an antecedent
midlatitude low with the post-tropical remnants of Helene. The
cyclone should remain centered over the lower Ohio Valley region,
drifting/wobbling erratically eastward over northern KY through the
period, while continuing to fill. The strongest associated mid/
upper-level winds should remain mostly behind a low-level frontal
zone extending from the northern Gulf across northern FL to the
coastal Carolinas. South of the boundary across parts of peninsular
FL, sufficient low-level moisture remains -- amid weak to negligible
MLCINH and a deep troposphere with modest but sufficient lapse rates
for convection. This will support scattered thunderstorms today
over FL, with isolated thunderstorm potential over coastal areas of
GA/Carolinas near the boundary. Dry midlevel air and lack of
greater flow/shear should keep severe potential too isolated and
disorganized for an outlook.
Elsewhere, just east of the mean ridge and amid northerly flow very
peripheral to the cyclone, a patch of marginally favorable low/
middle-level moisture should combine with diurnal heating of higher
terrain over parts of northern NM and southern CO. Scattered
showers are expected this afternoon, with isolated to widely
scattered convection extending above a mid/upper-level stable layer
and into icing regions suitable for lightning generation. Isolated
thunderstorms also are possible amid weak but sufficient low-level
moisture and instability around parts of the eastern Great Lakes.
..Edwards/Broyles.. 09/28/2024
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