Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1121 PM CST Sun Dec 21 2025

Valid 221200Z - 231200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Severe thunderstorms are not forecast today.

...Discussion...

Midlevel short-wave trough, off the Pacific Northwest coast, is
forecast to advance inland around 23/00z before deamplifying as it
ejects into southwest Canada by the end of the period. Associated
surface front will also progress inland around 23/00z, and cooling
lower tropospheric profiles should lead to weak buoyancy along the
WA/OR coast. Low-topped convection may generate a flash or two of
lightning, but thunderstorms should otherwise remain quite sparse.

Late-evening water-vapor imagery depicts a weak short-wave trough
over northeast Mexico, lifting north in line with latest model
guidance. Deep southeasterly flow across south TX will maintain
moist profiles that should exhibit modest SBCAPE by late afternoon.
Forecast soundings also suggest deep-layer shear will remain quite
weak, and any convection that evolves across this region should
remain below severe levels.

..Darrow/Squitieri.. 12/22/2025