SPC AC 280045
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0645 PM CST Thu Nov 27 2025
Valid 280100Z - 281200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
The risk for thunderstorms appears negligible across much of the
nation tonight.
...01Z Update...
Drying and stabilizing trends are now well underway across
southeastern Florida coastal areas and the Keys, where
lower/mid-tropospheric wind fields have veered to northwesterly.
Some lightning was noted earlier in a convective band within
west-southwesterly low-level flow emanating from Lake Ontario, where
trajectories across the relatively warm lake waters are maximized.
Additional convection occasionally becoming capable of producing
lightning appears possible to the east of Lake Ontario through at
least 05-06Z, before this potential becomes more negligible as mean
lower/mid-tropospheric winds begin to veer to a more
westerly/northwesterly component.
..Kerr.. 11/28/2025
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z
SPC AC 271720
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1120 AM CST Thu Nov 27 2025
Valid 281200Z - 291200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
A few thunderstorms are possible over the southern Plains and lower
Missouri Valley Friday night into early Saturday morning. Severe
thunderstorms are not currently expected.
...Synopsis...
Mid-level ridging over the central US will shift eastward behind a
departing trough over the East. A second trough will deepen over the
Rockies encouraging lee cyclogenesis over the southern Plains
Friday. As the surface low deepens, modest low-level moisture will
advect northward with a 40-60 kt southerly low-level jet. Lift from
the approaching trough and an attendant cold front will support
isolated thunderstorms from the southern Plains to the lower MO
Valley late Friday into early Saturday.
...Southern Plains into the lower Missouri Valley...
Ahead of the lee low, strong low-level warm air advection will
transport middling surface moisture northward over parts of
central/north TX into southern OK ahead of the surging cold front.
In the wake of the prior frontal passage, a persistent surface
stable layer is likely to prevent substantial northward moisture
return over the southern Plains. However, cold mid-level
temperatures (H5 temps -24C) beneath the deepening upper trough will
likely support some elevated buoyancy development late Friday,
overnight into Saturday. Isolated thunderstorms are possible within
the boarder warm advection band. While generally weak, (~250-500
J/kg MUCAPE) sufficient destabilization and strong flow aloft could
support an occasional stronger storm capable of small hail from
northeast TX into eastern OK and the Ozarks. But, given the limited
thermodynamics, a sustained severe risk appears unlikely.
..Lyons.. 11/27/2025
WUUS02 PTSDY2
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0700Z
SPC AC 271930
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0130 PM CST Thu Nov 27 2025
Valid 291200Z - 301200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PORTIONS OF
EASTERN TEXAS AND SOUTHWESTERN LOUISIANA...
...SUMMARY...
Isolated severe thunderstorms are possible across portions of
southeast Texas into western Louisiana Saturday afternoon or
evening.
...Synopsis...
The shortwave trough over the central Plains will move eastward as
mid-level westerly flow intensifies from the Plains to the MS Valley
and Midwest Saturday/Sunday. A surface low attendant to the trough
will move from OK/KS to the southern Great Lakes as a strong cold
front moves south from the Red River to the lower MS Valley.
Moisture return ahead of the front will support scattered
thunderstorms across eastern TX, the Sabine Valley and lower MS
valley through early morning Sunday.
...Southeast TX to western LA...
With southerly surface flow expected to develop ahead of the
deepening surface cyclone over the Plains Saturday, low-level
moisture advection should increase across coastal and southeast TX
into LA. A warm front will slowly lift northward, stalling over
southwest LA as it encounters a deep and cool air mass farther
north. Continued low-level warm air advection (despite ongoing
showers and remnant clouds) should allow for gradual destabilization
Saturday afternoon. While overall forcing for ascent appears weak as
the upper trough departs to the north, scattered thunderstorm
development appears probable, both within the low-level warm
advection regime and along the approaching cold front from the
Northwest. Given expected mid to upper 60s F dewpoints beneath 7-8
C/km mid-level lapse rates, around 1000 J/kg MLCAPE could support a
few stronger updrafts late Saturday through Sunday morning. Residual
westerly flow aloft may also favor some storm organization with
multicell lines or clusters and perhaps transient supercells capable
of damaging gusts and hail. This is most likely from the TX coastal
Plain to southwestern LA before the cold front moves offshore into
the Gulf.
..Lyons.. 11/27/2025
WUUS03 PTSDY3
NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0830Z
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