572 

ACUS03 KWNS 301930

SWODY3

SPC AC 301929



Day 3 Convective Outlook  

NWS Storm Prediction Center Norman OK

0129 PM CST Tue Dec 30 2025



Valid 011200Z - 021200Z



...NO SEVERE THUNDERSTORM AREAS FORECAST...



...SUMMARY...

Isolated thunderstorms are possible on New Year's Day across parts

of southern California and Arizona.



...Southern CA to AZ...

A mid/upper-level shortwave trough will move across parts of

southern CA Thursday morning, before dampening as it shifts eastward

across parts of the Desert Southwest and Four Corners region later

in the period. Cooling aloft atop modestly increasing low-level

moisture will support some early-day thunderstorm potential across

coastal southern CA. 



Guidance continues to vary regarding the strength, trajectory, and

magnitude of attendant flow fields of this system as it approaches

the coast. The somewhat stronger and farther south solutions (such

as the 12Z NAM/RRFS) depict potential for strong storm development

offshore, which could affect near-coastal areas of southern CA

during the morning before weakening. Other guidance (such as the 12Z

ECMWF) has trended northward, bringing stronger midlevel flow across

southern CA, but also greater displacement between substantial

cooling aloft and the more favorable low-level moisture. In general,

confidence in sufficient strengthening of flow within this weak

buoyancy regime remains too low to include severe probabilities. 



Uncertainty regarding the evolution of the shortwave extends

downstream into parts of the Desert Southwest, but an area of

modestly enhanced low-level moisture across southwest AZ could

support isolated storm development later in the day into the

evening, as some cooling aloft overspreads the region.



..Dean.. 12/30/2025



$$