409
FNUS21 KWNS 121639
FWDDY1

Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1138 AM CDT Sat Sep 12 2026

Valid 121700Z - 131200Z

A slight eastward expansion of the existing Elevated highlights was
made to capture potential impacts to the Sierra Nevada foothills in
the Sacramento Valley. In addition to the southwest to west winds of
10-15 mph (locally 20 mph at times) together with RH of around 20%
by mid afternoon, a more northwesterly wind component is expected
this evening and overnight as onshore/post frontal flow evolves.
Elevated highlights across the Great Basin were extended into
west-central UT where sustained southwest winds of 15-25 mph align
with RH of 15-20% this afternoon amid drying fuels.

Please see previous forecast discussion for additional details.

..Williams.. 09/12/2026

.PREV DISCUSSION... /ISSUED 0202 AM CDT Sat Sep 12 2026/

...Synopsis...
A deep upper low and associated 70-80 kt jet streak is forecast to
progress across the Pacific Northwest this afternoon and evening,
supporting an Elevated fire-weather threat across much of the Great
Basin and Sacramento Valley. Though meteorological conditions will
reach Critical criteria across portions of the outlook area, a lack
of receptive fuels will help suppress fire-weather concerns.

...Great Basin into the Sacramento Valley...
Sustained west/southwest winds of 15-20 MPH (potentially gusting as
high as 25-30 MPH) should overspread much of the Great Basin by
mid-afternoon, with relative humidity varying between 10 and 20%.
Though these conditions reach meteorological Critical criteria, fuel
conditions are relatively stable across much of the area, with ERCs
generally at or below the 70th annual percentile. While this should
limit overall concerns for wildfire ignition, any ignitions that
occur would be subject to rapid spread owing to the strong, gusty
winds. The corridor of strongest winds is forecast to be over
portions of northern Nevada into southeastern Oregon closer to the
core of the aforementioned jet streak.

Across the Sacramento Valley, winds should reach 15-20 MPH (with
locally higher gusts where terrain influences support it) by the
afternoon. However, a large onshore wind component will prevent
relative humidity from dropping below critical thresholds and a lack
of receptive fuels should suppress fire-weather concerns.

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

$$