557 
ACUS01 KWNS 221937
SWODY1
SPC AC 221936

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0136 PM CST Mon Dec 22 2025

Valid 222000Z - 231200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Severe thunderstorms are not expected today.

...20z Update...
The previous outlook reasoning remains on track and no changes were
made with this update.

..Bunting.. 12/22/2025

.PREV DISCUSSION... /ISSUED 1008 AM CST Mon Dec 22 2025/

...Synopsis...
A pronounced midlevel shortwave trough and associated baroclinic
zone will move across the WA coast later this afternoon. 
Low-midlevel lapse rates will contribute to weak buoyancy of
sufficient depth (through -20 C at the equilibrium level) for charge
separation and isolated lightning flashes with low-topped convection
along and behind the front.  Shallow, weakly rotating convection
will be possible near the WA coast per the KLGX VWP/hodograph, but
the threat for severe storms appears too limited to warrant an
outlook area.  Farther south, the potential for isolated lightning
flashes will slowly wane through the day across the northern Sierra
Nevada, where weak buoyancy rooted above the surface will likewise
diminish.

Otherwise, a broad subtropical ridge (with unusually high
geopotential heights) covers the southern Plains/Gulf coast.  An
embedded/weak midlevel trough will rotate slowly north-northwestward
around the periphery of the ridge, bringing weak ascent and an
associated moisture plume into south TX.  Per the observed deepening
of the moist layer at BRO in the past 12 hours, pockets of surface
heating/destabilization could support isolated thunderstorm
development across south TX this afternoon.

$$