Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0625 AM CST Wed Dec 31 2025

Valid 311300Z - 011200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Isolated thunderstorms are possible along coastal southern
California very late in the period.

...Southern CA...
A southern-stream upper-level trough will approach the southern CA
coast late tonight. Latest model guidance suggests increasing
large-scale ascent will approach the coast, contributing to isolated
convection along/ahead of a weak front as it surges inland,
primarily after 09z. Forecast soundings along the coast suggest
thunderstorms should be elevated in nature, with initial convection
likely rooted at or above 850mb. Weak buoyancy and shear suggests
minimal potential for severe storms prior to 12z Thursday.

..Bunting/Weinman.. 12/31/2025

Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0228 AM CST Wed Dec 31 2025

Valid 021200Z - 031200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
General thunderstorms are forecast, mainly Friday night into early
morning Saturday, across the central Gulf Coast and Deep South, as
well as along a portion of the Pacific Coast.

...Central Gulf Coast and Deep South...
At least isolated thunderstorm potential should return across a
portion of the interior Deep South on Friday night. Meager elevated
buoyancy should develop as low-level moistening occurs ahead of a
leading shortwave impulse tracking across the Mid-South to TN
Valley. This impulse may dampen downstream of a shortwave trough
progressing from the Four Corners to north TX. The bulk of MUCAPE
should largely remain at around 500 J/kg or less, owing to modest
mid-level lapse rates.

Farther south towards the central Gulf Coast from southeast LA to
the FL Panhandle, richer low-level moisture should spread somewhat
inland ahead of the more prominent shortwave trough. Most
convective-parameterized models suggest an increase in convective
development may occur at the end of the period within the low-level
theta-e gradient. Despite a generally zonal deep-layer wind profile,
adequate low-level hodograph curvature and robust speed shear
renders a conditional supercell concern. But poor mid-level lapse
rates renders concern for the degree of convective development prior
to 12Z, with the 00Z RRFS having minimal deep convective signal.
With minimal ML probabilities across this area as well, will defer
to later outlook cycles for a level 1-MRGL risk highlight. 

...Coastal northern CA and southwest OR...
A large-scale upper trough will approach the Pacific Coast, with an
intense mid-level jetlet likely impinging on the northern CA coast
on Friday night. Fast deep-layer flow is anticipated within the
low-level warm conveyor, but should remain entirely meridional until
near the end of the period. Instability within the warm conveyor
appears minimal, suggesting that thunderstorm potential will remain
negligible amid strong gradient flow. Steepening mid-level lapse
rates may brush the northern CA to southwest OR coast in the early
morning Saturday. This should support scant buoyancy and potential
for very isolated thunderstorms.

..Grams.. 12/31/2025

Day 4-8 Convective Outlook  
NWS Storm Prediction Center Norman OK
0351 AM CST Wed Dec 31 2025

Valid 031200Z - 081200Z

...DISCUSSION...
Primary severe concern will be across the northeast Gulf Coast
States, during the morning to afternoon on D4/Saturday. A
lower-amplitude shortwave trough remains consistently progged to
dampen as it progresses quickly across the Southeast and northeast
Gulf. With a weak surface cyclone, low-level winds should remain
veered. But this should be adequate for weak buoyancy to spread
east, emanating from the northwest Gulf and LA. With a more robust
convective signal closer to the coast compared to D3/Friday, at
least a level 1-MRGL risk should be warranted. This is supported by
latest SPC-CSU and NSSL GEFS-based ML guidance with overlapping 5
percent probability areas. 

Along coastal CA, while run-to-run predictability is poor, latest
guidance has some signal for low-topped supercell potential this
weekend, downstream of a large-scale trough off the Pacific Coast.
This appears generally focused across northern CA on D4/Saturday,
shifting to southern CA on D5/Sunday. Spatiotemporal aspects of
individual shortwave impulses and attendant mid-level jetlets
relative to probable scant/meager buoyancy profiles will be crucial
for delineating areal highlights in shorter-term outlooks.

Otherwise, a combination of low potential/predictability remains
evident early next week.