353
ACUS01 KWNS 160528
SWODY1
SPC AC 160526

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1126 PM CST Sat Nov 15 2025

Valid 161200Z - 171200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Isolated thunderstorms are possible across the Four Corners states
and along the California coast late tonight. Severe storms are not
expected.

...Western U.S...

Large-scale pattern does not appear particularly favorable for
robust convection across the CONUS Sunday. Even so, isolated
thunderstorms are expected across a few areas of the western U.S.,
primarily ahead of two strong troughs. The lead midlevel trough will
eject across the lower CO River Valley early in the period with
high-level diffluent flow spreading across the Four Corners region
during the afternoon. This feature will eject as a negative-tilted
trough resulting in cool midlevel temperatures and steep lapse
rates. Forecast soundings exhibit meager instability, but likely
adequate for lightning in the strongest updrafts.

A secondary trough is forecast to approach the northern CA Coast
during the latter half of the period. 500mb speed max will dig
toward the back side of this feature, but not advance inland until
later in the day2 period. At this time it appears the synoptic front
will approach the northern CA Coast around 17/12z, along with a bit
more instability beneath the approaching trough. Most lightning
activity should remain offshore, but isolated storms may approach
the Coast by the end of the period.

..Darrow/Moore.. 11/16/2025

$$