RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Thu Dec 11 07:35:02 UTC 2025.
No Mesoscale Discussions are in effect as of Thu Dec 11 07:35:02 UTC 2025.
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1153 PM CST Wed Dec 10 2025
Valid 111200Z - 121200Z
...NO THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Thunderstorms are not forecast across the U.S. on Thursday.
...DISCUSSION...
A mid-level trough will move eastward from the eastern U.S. into the
western Atlantic today, as northwest flow remains over most of the
nation. At the surface, a large area of high pressure will be
located from parts of the Great Plains to the southern and central
Appalachians. The relatively cool and dry airmass will be
unfavorable for thunderstorm development across the U.S. through
tonight.
..Broyles/Thornton.. 12/11/2025
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SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1129 PM CST Wed Dec 10 2025
Valid 121200Z - 131200Z
...NO THUNDERSTORM AREAS FORECAST...
...SUMMARY...
The risk for thunderstorms appears negligible across much of the
U.S. Friday through Friday night.
...Discussion...
Downstream of a blocking mid-level high, maintaining near/north of
the Aleutians, it still appears that the evolving flow may include a
shortwave ridge building inland across British Columbia and the
Pacific Northwest during this period. As this occurs, digging short
wave troughs farther downstream may reinforce larger-scale mid-level
troughing across parts of the northern Great Plains through Great
Lakes vicinity. However, in general, models indicate that the
persistent cyclonic regime to the east of the Rockies may gradually
lose amplitude, with the stronger mid-level height gradient
tending to recede northward through the middle Mississippi/Ohio
Valleys and Mid Atlantic. In lower levels, a leading surge of
colder air to the lee of the Rockies may stall and weaken across the
Mid South through south central Great Plains vicinity by late Friday
night.
In lower latitudes, mid-level heights may rise on the northwestern
periphery of Atlantic subtropical ridging, as far north as southern
Florida, downstream of weak mid/upper trough progressing across the
northern Mexican Plateau through northwestern Gulf Basin. Beneath
this regime, it appears that gradual Gulf boundary-layer moistening
will continue. In the vicinity of a weak surface trough forecast to
develop near Texas coastal areas by late Friday night, it is
possible that destabilization and forcing for ascent may become
conducive to scattered deepening convective development prior to 12Z
Saturday.
...Texas coastal areas...
Latest guidance, including available forecast soundings from various
models, still suggests that the environment may become increasing
conducive to convection capable of producing lightning near lower
through middle coastal areas late Friday night. Highest
probabilities for the initiation of at least a couple of weak
thunderstorms may be around 12Z Saturday, just east of the coastal
waters. At least for now, thunderstorm probabilities will be
maintained at less than 10 percent, but, depending on trends in
later model runs, it is possible than minimum threshold thunderstorm
probabilities may still need to be reintroduced.
..Kerr.. 12/11/2025
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SPC 0830Z Day 3 Outlook
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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SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1135 PM CST Wed Dec 10 2025
Valid 111200Z - 121200Z
...NO CRITICAL AREAS...
...Synopsis...
Fire weather concerns are expected to remain low today. The pattern
will favor high amplitude ridging across the western US and
troughing across the eastern US. Westerly flow across the northern
Rockies and surface troughing across the Plains will allow for some
overlap of downslope flow with dry conditions across the central and
southern High Plains. Across eastern Colorado into southeastern
Wyoming, west-northwest sustained winds of 15-30 mph will overlap
minimum RH of 15-30%. Across west Texas into central Oklahoma, areas
of overlap of southwest sustained winds of 10-20 mph and minimum RH
of 15-25% will be possible. Fuels across both of these regions
remain marginal and are not receptive to large fire spread, which
will preclude inclusion of any areas at this time.
..Thornton.. 12/11/2025
...Please see www.spc.noaa.gov/fire for graphic product...
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SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1137 PM CST Wed Dec 10 2025
Valid 121200Z - 131200Z
...NO CRITICAL AREAS...
...Synopsis...
Fire weather concerns are expected to remain low on D2/Friday. The
pattern will remain fairly similar to D1, with ridging across the
western US and troughing in the east. Breezy conditions will
continue across the central and southern High Plains as a cold front
shifts southward into towards coastal Texas through the end of the
period. Some overlap of localized brief windy/dry conditions will be
possible across portions of western Texas into eastern New Mexico.
Overall, localized potential for any Elevated conditions and
marginal fuels will preclude the need to include areas at this time.
..Thornton.. 12/11/2025
...Please see www.spc.noaa.gov/fire for graphic product...
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