RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Tue Dec 23 09:44:02 UTC 2025.
No Mesoscale Discussions are in effect as of Tue Dec 23 09:44:02 UTC 2025.
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1119 PM CST Mon Dec 22 2025
Valid 231200Z - 241200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Thunderstorm potential will increase along the California coast late
tonight. Organized severe is not currently forecast.
...CA...
Strong short-wave trough is forecast to approach the northern CA
coast after 24/06z, then eject inland by sunrise as midlevel speed
max intensifies and translates into northern CA. Latest model
guidance suggests this feature will induce a surface low that should
deepen as it approaches the northern CA/OR coast. This evolution
will allow a notable surface front to surge inland toward the end of
the period, around 24/12z. Wind profiles are expected to increase
markedly ahead of this feature, but pre frontal buoyancy will remain
quite limited. Forecast soundings support this with roughly 100-200
J/kg MUCAPE expected just ahead of the front. Given the strength of
the wind field there is some concern that a few strong gusts could
be noted with deeper convection; however, this activity should
develop very late (after 09z), possibly becoming more problematic
during the day2 period. At this time will not introduce severe
probabilities due to the expected late-period development, but will
continue to monitor for possible upgrade.
...South TX...
Weak midlevel disturbance is lifting north into deep south TX late
this evening. Forecast soundings suggest modest SBCAPE will develop
by mid day as this feature progresses north of the international
border. Wind fields should remain weak, along with forcing, so the
risk of severe is expected to remain low this period.
..Darrow/Squitieri.. 12/23/2025
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SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
0100 AM CST Tue Dec 23 2025
Valid 241200Z - 251200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ALONG PARTS OF
THE CALIFORNIA COAST AND INLAND IN THE SAN JOAQUIN VALLEY...
...SUMMARY...
Thunderstorms with marginally severe wind gusts, hail and
potentially a brief tornado will be possible from Wednesday into
Wednesday night along parts of the California coast, and inland
across the San Jouquin Valley.
...California...
A ridge aloft will move eastward across the central U.S. on
Wednesday, as a mid-level trough moves eastward across the eastern
Pacific. Ahead of this large-scale feature, a subtle shortwave
trough will approach the California coast Wednesday afternoon. As
heights gradually fall, large-scale ascent and mid-level moisture
will overspread most of California during the day. Thunderstorm
development will be possible along the central and southern
California coast, and inland across the San Joaquin Valley. The
greatest chance for severe storms will be as the left exit region of
a 90 to 100 knot mid-level jet moves across the San Joaquin Valley
during the mid to late afternoon. Near this feature, very strong
deep-layer shear will exist and MUCAPE is expected to peak in the
500 to 750 J/kg range. This should be enough for a few
semi-organized storms with a threat for hail and marginally severe
gusts. A brief tornado will also be possible. An isolated severe
threat is expected to continue into the overnight period, and may
shift southward along the coast into southern California, as a
second minor impulse approaches and moves inland.
..Broyles.. 12/23/2025
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SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0215 AM CST Tue Dec 23 2025
Valid 251200Z - 261200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ALONG PARTS OF
THE CENTRAL AND SOUTHERN CALIFORNIA COAST...
...SUMMARY...
Thunderstorms with marginally severe wind gusts and perhaps a brief
tornado, will be possible on Thursday along parts of the central and
southern California Coast.
...California...
A large-scale mid-level trough will move slowly eastward toward the
California coast on Thursday. Strong flow aloft will maintain a
stream of mid-level moisture into the region, as large-scale ascent
continues to support scattered thunderstorm development. At the
surface, a cold front will approach the central California coast
during the day. Surface dewpoints ahead of the front will be in the
50s F, southward into parts of southern California. This should be
enough for weak destabilization near the coast during the late
morning and afternoon, which could result in a marginal severe
threat. Strong low to mid-level flow and modestly steep low-level
lapse rates could support isolated severe wind gusts and perhaps a
brief tornado.
..Broyles.. 12/23/2025
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Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0341 AM CST Tue Dec 23 2025
Valid 261200Z - 311200Z
...DISCUSSION...
From Friday/Day 4 to Sunday/Day 6, a mid-level ridge is forecast to
move eastward from the central U.S. to the Eastern Seaboard. During
this time, a trough is forecast to develop in the Pacific Northwest,
and then to dig southeastward into the mid Mississippi Valley. An
associated cold front is forecast to move southeastward into the
Ohio and Tennessee Valleys by Sunday afternoon. Ahead of the front,
surface dewpoints in the 60s F should result in weak destabilization
with thunderstorm development possible along the front. However, the
models suggest that most of the convection will be post-frontal.
This limitation should keep any severe threat marginal.
On Monday/Day 7 and Tuesday/Day 8, the trough is forecast to move
across the eastern U.S. into the western Atlantic, with the front
moving off the Atlantic coast. In its wake, a relatively dry and
cool airmass will make thunderstorm development unlikely across most
of the nation.
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SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0118 AM CST Tue Dec 23 2025
Valid 231200Z - 241200Z
...NO CRITICAL AREAS...
...Synopsis...
Upper ridging will remain in place east of the Rockies while a
highly amplified mid-level trough impinges on the West Coast today.
Surface lee troughing will encourage moisture return across the
Plains states, with relatively drier air meandering along the
immediate lee of the Rockies. Surface winds along the southern into
central High Plains will be relatively weak on a large-scale basis
though, with wildfire-spread concerns remaining localized at best.
..Squitieri.. 12/23/2025
...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
0118 AM CST Tue Dec 23 2025
Valid 241200Z - 251200Z
...Synopsis...
A mid-level ridge will persist across the central U.S., with a
highly amplified mid-level trough poised to gradually drift eastward
across the Interior West tomorrow (Wednesday). Lee troughing across
the High Plains will intensify through the day, promoting a modestly
stronger surface wind field across the southern High Plains compared
to Day 1. 15 mph sustained westerly surface winds will coincide with
15-20 percent RH during the afternoon across northeast New Mexico
into the Texas Panhandle and far southwestern Kansas. Given dry
fuels over this region, Elevated highlights have been introduced.
..Squitieri.. 12/23/2025
...Please see www.spc.noaa.gov/fire for graphic product...
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