Trowbridge, California Weather Forecast Discussion

069
FXUS66 KSTO 252018
AFDSTO
Area Forecast Discussion
National Weather Service Sacramento CA
118 PM PDT Thu Sep 25 2025
For additional details on weather and expected impacts over the
next 7 days, please visit weather.gov/sto/briefing.
.SYNOPSIS...
An unsettled pattern continues through the next 7 days. First
system will continue to bring showers and isolated storms today
and Friday through Sunday for the Sierra. Critical fire weather
conditions Friday for the northern Sacramento Valley from hot,
dry, and breezy conditions. Confidence continues to increase for
cool temperatures and widespread rain early next week.
&&
.KEY MESSAGES...
* TONIGHT - FRIDAY:
- System continues to track across CA this afternoon and evening
   bring showers to the Foothills, Valley, and Delta from I-80
   south and showers/storms to the mountains south of I-80. Expect
   showers to diminish this evening for the Valley, Delta, and
   Foothills, with continued chances for showers and isolated
   storms tomorrow afternoon around the Sierra Crest.
- Early Friday morning through early Saturday morning RH values
   drop, northerly winds become breezy, and temperatures warm
   quickly. This results in critical fire weather conditions for
   the northern Sacramento Valley. A Red Flag Warning is in effect
   for the northern Sacramento Valley from 5am Friday through 5am
   Saturday.
* SATURDAY THROUGH WEDNESDAY:
- Isolated showers and storms both Saturday and Sunday for areas
   within the Sierra Crest mainly south of Hwy 50 Saturday and
   along the rest of the Sierra Sunday.
- Confidence continues to increase for an early week widespread
   rain event affecting the forecast area. Nearly all ensembles
   have great agreement on a trough moving into the CA coastline
   and digging into southern CA. Probabilities of seeing over an
   inch of QPF Monday through Wednesday is 60-80 percent along the
   southern Cascades, back through the Coastal Range. 20 to 30
   percent chance for over and within the Sacramento Valley and
   lower as you head towards the San Joaquin Valley. This is the
   transition season, so still a chance models may be being too
   aggressive, but at this time confidence is increasing.
.AVIATION...
A few showers in the area should remain mainly in the higher
terrain. These showers should diminish this evening. Isolated
mountain showers and thunderstorms are then expected again
tomorrow afternoon but nothing is expected at lower elevations.
Ceiling will remain VFR with general light winds.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from 5 AM Friday to 5 AM PDT Saturday for
Northern Sacramento Valley to Southern Tehama County Line Below
1000 Ft.
&&
$$

NWS STO Office Area Forecast Discussion