SPC 1730Z Day 2 Outlook

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1124 AM CST Wed Dec 31 2025

Valid 011200Z - 021200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR COASTAL
SOUTHERN CA...

...SUMMARY...
Locally damaging winds and a brief tornado are possible along a
portion of coastal southern California on New Year's Day morning.

...Southern CA...
A compact midlevel shortwave trough is forecast to move across parts
of southern CA toward the San Joaquin Valley through the day, before
dampening somewhat as it approaches the Great Basin during the
evening. The strongest DCVA and cooling aloft will generally be
displaced north of the most favorable low-level moisture, but some
thunderstorm potential will continue to accompany this system for at
least the first part of the day. 

The greatest relative potential for surface-based convection appears
to be across immediate coastal areas of southern CA and adjacent
offshore regions, where surface dewpoints are forecast to increase
into the low 60s F. Deep-layer shear will not be particularly
strong, but 30-40 kt of 700 mb flow and modest enlargement of
low-level hodographs could support potential for weakly rotating
storms. While confidence in sufficiently robust convection is not
high, locally damaging wind and/or a brief tornado cannot be ruled
out with any stronger cells near the coast, primarily during the
morning.

..Dean.. 12/31/2025

SPC Day 1 Fire Weather Outlook

Day 1 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
1058 AM CST Wed Dec 31 2025

Valid 311700Z - 011200Z

...Southeast and Florida...
Elevated highlights were removed for portions of southern GA and the
FL Panhandle as light winds less than 10 mph and marginal fuel
dryness limits a broader fire weather threat for this area. Elevated
highlights continue for the eastern FL Peninsula, much of GA and the
Carolinas as dry conditions with RH falling as low as 20-25 percent
this afternoon amid a dry continental air mass. See previous
discussion for more details.

...Central/Southern High Plains...
Dry, downslope flow continues across the southern and central High
Plains, supporting low relative humidity in the 15-25% range this
afternoon within the region. However, relatively weak northwest flow
aloft and a diffuse surface pressure gradient will present a more
localized elevated fire weather threat just leeward of the
central/southern Rockies this afternoon. West-northwest winds of 15
mph and RH dropping to around 15% are expected, but marginal fuel
dryness should limit a more substantial wildfire potential.

..Williams.. 12/31/2025

.PREV DISCUSSION... /ISSUED 0113 AM CST Wed Dec 31 2025/

...Synopsis...
A pronounced mid-level trough will progress south-southeastward
while amplifying over the Northeast today, supporting surface
troughing along the East Coast as surface high pressure overspreads
the Midwest. Dry offshore flow should occur by afternoon peak
heating from the Carolinas to the Florida Peninsula. 10 mph
sustained northwesterly surface winds amid 25-35 percent RH will
encourage localized wildfire-spread potential amid dry fuels, with
Elevated highlights remaining in place. Surface lee troughing across
the Plains will encourage breezy downslope conditions along the
central and southern High Plains, though RH appears too high for
Elevated conditions at this time.

...Please see www.spc.noaa.gov/fire for graphic product...

SPC 1630Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1010 AM CST Wed Dec 31 2025

Valid 311630Z - 011200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Isolated thunderstorms may occur across parts of southern California
late tonight into early Thursday morning.

...Synopsis and Discussion...
With upper ridging remaining prominent over the western CONUS and
upper troughing centered across the eastern states, thunderstorm
potential should remain minimal though tonight for a large majority
of the CONUS. One exception will be across parts of southern CA late
tonight into early Thursday morning, as an upper trough/low over the
eastern Pacific gradually approaches the CA Coast by the end of the
period. While low-level moisture and related instability are both
expected to remain limited, increasing large-scale ascent and
gradually cooling mid-level temperatures preceding the upper
trough/low may still support isolated convection capable of
producing occasional lightning flashes, mainly after 01/06Z. Both
MUCAPE and deep-layer shear appear too weak to support a meaningful
threat for organized severe thunderstorms through the end of the
period (12Z Thursday morning).

..Gleason/Wendt.. 12/31/2025