ACUS03 KWNS 110733
SWODY3
SPC AC 110732
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0132 AM CST Thu Dec 11 2025
Valid 131200Z - 141200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Scattered, mostly weak, thunderstorm activity is possible across the
Gulf Coast states Saturday into Saturday night.
...Discussion...
Models indicate that the blocking high will generally maintain
strength just to the north of Aleutians through this period. The
evolution of a lower/mid-tropospheric cyclone to its east, across
the northeastern Pacific, is more unclear, but guidance indicates
that a downstream ridge will broaden eastward, inland of the British Columbia/Pacific Northwest coast through the southern Canadian
Prairies and northern U.S. Great Plains. Farther east, it still
appears that a vigorous digging short wave trough will once again
contribute to larger-scale mid-level trough amplification across the
Upper Midwest into Great Lakes and Ohio Valley Saturday through
Saturday night.
An increasingly confluent mid-level regime, in the wake of the
amplifying trough, is forecast to support the southeastward
development of an expanding cold surface ridge to the east of the
Rockies, across much of the Great Plains and Mississippi Valley
through western slopes of the Appalachians. By late Saturday night,
a strengthening low-level baroclinic zone, near the leading edge of
the colder air, is forecast to approach southern Mid Atlantic
through Gulf coastal areas.
In lower latitudes, beneath a weak branch of westerlies emanating
from the subtropical eastern Pacific, a remnant preceding surface
frontal zone may shift northward across the Florida Keys and
southern peninsula by 12Z Sunday, downstream of broad mid-level
troughing overspreading the Gulf Basin.
...Gulf Coast states...
Although weak lapse rates and rather weak lower/mid-tropospheric
wind fields seem likely to minimize the risk for severe weather, a
substantive increase in boundary-layer moisture, in the presence of
increasing large-scale forcing for ascent, may support increasing
scattered thunderstorm development along the front, near the Florida
Keys and southern peninsula, by late Saturday night.
Elsewhere, guidance suggests that scattered thunderstorm development
is possible near/offshore of lower through middle Texas coastal
areas, at least early Saturday. Farther northeast, a narrow plume
of elevated moisture return, off the modifying northwestern Gulf
boundary layer, might contribute to weak destabilization sufficient
for convection capable of producing lightning, mainly just ahead of
the front as it approaches the Gulf coast late Saturday night.
..Kerr.. 12/11/2025
$$
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