RSS Mesoscale Discussions from Storm Prediction Center
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1100 PM CST Thu Nov 27 2025
Valid 281200Z - 291200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Weak thunderstorm activity may begin to develop across parts of
western Texas by this afternoon, before increasing within an
expanding area of precipitation across parts of the central and
southern Great Plains toward lower Missouri and Mississippi Valleys
tonight.
...Discussion...
Downstream of amplifying flow, including building mid/upper ridging
across the mid-latitude eastern Pacific, it appears that at least a
couple of short wave perturbations may consolidate into larger-scale
digging troughing across and east of the Canadian and northern U.S.
Rockies later today through tonight. There is notable spread still
evident within/among the model output concerning this evolution, but
models generally indicate that this will be accompanied by modest
surface cyclogenesis across parts of eastern Colorado into the
adjacent central Great Plains by 12Z Saturday.
This is close on the heels of a cool/dry intrusion still ongoing
across the central into southwestern Gulf Basin, in the wake of
amplified mid/upper troughing approaching the Atlantic Seaboard.
However, the most significant short wave perturbation still digging
within this regime is forecast to rapidly accelerate into the
northwestern Atlantic today through tonight, and trailing surface
ridging likely will begin shifting east of the southern Great
Plains/lower Mississippi Valley. Models suggest that this will
occur in a manner allowing for a strengthening southerly return flow
from the Texas South Plains/lower Rio Grande Valley toward the lower
Missouri Valley by late tonight.
This may be accompanied by rapid north-northeastward advection of
moisture now present across/east of the Mexican Plateau, and include
near-surface dew points increasing through the mid 50s to lower 60s
F across Deep South Texas into portions of western North Texas by
the end of the period. However, to the north of Deep South Texas,
where relatively warm mid-level temperatures probably will inhibit
thunderstorm development, the moisture return is generally forecast
above a residual cool/stable near-surface layer, which will remain
deeper with northward/eastward extent into the central Great Plains
and lower/middle Mississippi Valley.
Still, forecast soundings indicate that this moistening, near the
base of a layer of steepening lapse rates aided by
lower/mid-tropospheric warm advection, will provide support for
convective development capable of producing lightning. It appears
that this could initiate across the Permian Basin vicinity by this
afternoon, if not perhaps earlier, before forcing for ascent
supports increasingly widespread convection and embedded weak
thunderstorm activity across parts of the southern into central
Great Plains and lower Missouri Valley tonight.
..Kerr/Weinman.. 11/28/2025
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SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1255 AM CST Fri Nov 28 2025
Valid 291200Z - 301200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
EASTERN TX INTO THE ARKLATEX AND SABINE RIVER VALLEY...
...SUMMARY...
Isolated severe thunderstorms are possible across portions of
southeast Texas into western and central Louisiana tomorrow
(Saturday) afternoon or evening.
...Synopsis...
A mid-level trough will traverse the central Plains and Middle MS
Valley tomorrow (Saturday), resulting in the rapid northeastward
progression of a surface low, with a cold front poised to surge
southward across the southern Plains toward the Arklatex. Seasonal
moisture will advect northward in advance of the surface low across
much of central and eastern TX to the Sabine River Valley, promoting
enough buoyancy, amid strong deep-layer ascent, for thunderstorm
development. Given the expected presence of a strong southerly
low-level jet and accompanying vertical wind shear, isolated strong
to severe thunderstorms are possible.
...Eastern TX to the Arklatex and Sabine River Valley...
Widespread showers and thunderstorms should be ongoing at the start
of the period (12Z Saturday) due to an ongoing warm-air advection
regime, driven by a 40-50 kt southwesterly low-level jet. While
low-level cloud cover should persist for much of the day across
eastern TX into the Sabine River Valley, pockets of occasional
heating will help boost surface temperatures into the upper 60s F.
Should this occur, mid 60s F surface dewpoints beneath 7+ C/km
mid-level lapse rates, may yield MLCAPE approaching 1000 J/kg in
spots. The latest guidance consensus depicts two general focal
points for thunderstorm initiation. One is along the approaching
cold front in northeast TX into southwestern AR and far northwestern
LA by early afternoon, where linear convection may develop and
support severe gusts. Ahead of the cold front, low-level confluence
bands, over the TX coastal plain, within the primary moisture axis
of the warm-air advection regime, may also support thunderstorm
initiation. Despite the departing nature of the low-level jet,
appreciable south-southwesterly 850 mb flow (30+ kts), beneath 50+
kt west-northwesterlies glancing the Arklatex, will support
elongated hodographs and up to 40 kts of effective bulk shear.
Transient supercells may develop in these confluence bands by
afternoon into the evening hours, capable of an instance or two of
severe wind/hail, and perhaps even a tornado.
..Squitieri.. 11/28/2025
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