FNUS21 KWNS 150608
FWDDY1

Day 1 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
0107 AM CDT Thu Oct 15 2026

Valid 151200Z - 161200Z

...CRITICAL FIRE WEATHER AREA FOR WESTERN L.A. COUNTY AND
SOUTHEASTERN VENTURA COUNTY...

...Synopsis...
A mid-level low over the central Plains will weaken and transition
to an open wave, quickly becoming absorbed within defined troughing
over the Upper Midwest. Meanwhile, a cutoff low will detach into the
Desert Southwest as surface high pressure migrates into the
Intermountain West and central CONUS. As a result, an increasing
offshore pressure gradient will promote a fire weather threat for
portions of southern CA that have not seen recent rainfall. 

...Southern California...
The fire weather threat will increase markedly early this morning
into the early afternoon hours as offshore flow accelerates across
portions of southern CA. Resultant east-northeast winds of 15-25 mph
will emerge with related downslope drying from a dry airmass
originating from the Colorado Plateau, allowing for RH reductions as
low as 10%. A corridor of stronger east-northeast winds of 20-30 mph
with gusts of 40-50 mph coupled with low RH will support critical
fire weather conditions in the Simi Valley area of western L.A.
county and southeastern Ventura county.

...Sierra Nevada, portions of the Sacramento Valley and Napa
Valley...
Increasing easterly downslope flow and drying into the Sacramento
Valley will promote elevated fire weather conditions for the Sierra
Nevada foothills this afternoon. Poor overnight RH recoveries with
some locations not exceeding 30% will precondition fuels where ERCs
are at the 80-90th percentiles. East winds of 10-15 mph (locally
20-25 mph in favored valley corridors) and daytime RH of 15% will
support an Elevated fire weather threat.

A building ridge aloft supporting above normal temperatures and very
dry conditions along with offshore flow trajectories will bring a
fire weather threat to portions the Sacramento Valley and adjacent
Napa Valley area. North winds of around 15 mph in the Sacramento
Valley will transition to east-northeast over Napa Valley and nearby
coastal ranges as RH falls to as low as 10% by this afternoon.

..Elizalde-Garcia.. 10/15/2026

...Please see www.spc.noaa.gov/fire for graphic product...

$$