Convective Weather Outlook

ACUS02 KWNS 011714
SWODY2
SPC AC 011712

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1112 AM CST Thu Jan 01 2026

Valid 021200Z - 031200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Severe thunderstorm potential appears low on Friday.

...Central Gulf Coast and Deep South...
A low-amplitude midlevel shortwave trough will move from the
south-central Plains toward the TN Valley through the period, while
a somewhat more vigorous shortwave progresses east-southeastward
from the Four Corners region toward the lower MS Valley. The
combination of these features will result in an elongated surface
low that will extend from northern MS/AL toward southern LA by
Friday evening. 

Returning low-level moisture will result in a somewhat conditionally
favorable environment Friday afternoon from parts of LA into
southern MS, as MLCAPE increases to around 500 J/kg amid
strengthening deep-layer shear. However, poor midlevel lapse rates
and generally weak ascent across the warm sector may tend to limit
surface-based storm potential, with most guidance showing no diurnal
development across this area. A strengthening low-level jet will aid
in the development of elevated convection Friday evening, mainly
across parts of central/northern MS/AL/GA. Weak buoyancy should tend
to limit the organized severe threat with any elevated storms.
Convection may also tend to increase along the immediate central
Gulf Coast near the end of the period, but warm midlevel
temperatures are expected to limit storm depth and intensity in this
area through 12Z Saturday morning. 

...Northern CA into southwest OR...
A deep mid/upper-level trough and embedded deep-layer cyclone will
gradually approach the central and northern Pacific Coast through
the period. Within the large-scale trough, an embedded vorticity
maximum is forecast to approach northern CA and southwest OR by mid
to late evening. Colder temperatures aloft and some steepening of
midlevel lapse rates will overspread the region as this vorticity
maximum moves through, which will increase the threat for sporadic
lightning flashes with any stronger convective elements. 

Most CAM guidance depicts development of a narrow rain band in
association with the lead vorticity maximum, which moves over
immediate coastal regions between 03-06Z. This band may be
coincident with gusty/locally damaging winds, given the
strengthening background wind field (50+ kt at 850 mb). However,
with stronger cooling aloft and steepening of low-level lapse rates
generally only expected in the wake of this band, the extent to
which any deeper convective processes contribute to wind-damage
potential is uncertain and may remain limited.

..Dean.. 01/01/2026

$$

ACUS03 KWNS 011930
SWODY3
SPC AC 011929

Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0129 PM CST Thu Jan 01 2026

Valid 031200Z - 041200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE
SOUTHEAST...AND ALSO FROM PARTS OF NORTHERN CA INTO COASTAL
SOUTHWEST OR...

...SUMMARY...
Isolated severe storms are possible across parts of the Southeast on
Saturday, and the Sacramento and northern San Joaquin Valleys to
coastal northern California-southwest Oregon during the late
afternoon to evening.

...Parts of the Southeast...
A positive-tilt mid/upper-level shortwave trough is forecast to move
from the lower MS Valley toward the South Atlantic Coast through the
period, as an attendant surface low moves from parts of AL/GA to
offshore of SC by late evening. A trailing cold front will move
through parts of the Southeast and central Gulf Coast vicinity. 

Guidance continues to vary regarding the timing of the front and
extent of heating/destabilization across the warm sector, but a
plume of weak to moderate MLCAPE is expected to be in place
along/ahead of the cold front during the afternoon, as low-level
moisture spreads northeastward. Some veering/weakening of low-level
flow is forecast across parts of the warm sector with time
(especially with southwestward extent), but increasing midlevel flow
will result in sufficient effective shear for organized storms,
including some supercell potential. 

Any lingering morning convection may intensify during the afternoon,
with additional storm development expected along/ahead of the cold
front, and near the primary buoyancy gradient and effective warm
front. This activity could pose at least a low-probability threat
for all severe hazards. A corridor of somewhat greater potential may
evolve within the broader Marginal Risk area, though uncertainty
remains regarding the magnitude of diurnal heating/destabilization,
and the strength/timing of the primary shortwave trough as it moves
quickly eastward.

...Northern CA to coastal southwest OR...
Latest guidance still depicts potential for multiple shortwave
troughs to eject northeastward from a deep mid/upper-level trough
off of the Pacific Coast. The southernmost shortwave is forecast to
move across central CA through the afternoon, while the more
vigorous northern shortwave is expected to affect coastal OR from
late afternoon into the evening. 

The southern shortwave will be favorably timed for diurnal
convective development across the Sacramento and northern San
Joaquin Valleys, where cooling midlevel temperatures (dropping below
-20C at 500 mb) may support SBCAPE of 250-500 J/kg during the
afternoon. With relatively elongated hodographs, this generally
meager buoyancy may be sufficient for transient rotating cells to
develop, which could pose a threat for a brief tornado, small hail,
and locally gusty winds. 

The northern shortwave will be accompanied by a renewed
strengthening of low-level flow, potentially increasing to
near/above 60 kt at 850 mb over the ocean and along the northern
CA/southwest OR coast. Buoyancy will remain meager, but cold
temperatures aloft will support low-topped convection that could
contribute to severe-gust potential. Transient rotating cells may
also develop offshore and approach the coast.

..Dean.. 01/01/2026

$$