961
FNUS28 KWNS 202131
FWDD38

Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0429 PM CDT Wed Aug 20 2025

Valid 221200Z - 281200Z

An upper-level ridge oriented southeast-northwest will amplify over
the West into the weekend, with monsoonal moisture moving into
California, the Great Basin, and portions of the Northwest and Rocky
Mountain Areas. Well above normal temperatures are expected for much
of the West, especially ahead and away from the cloud cover and wet
thunderstorms associated with the monsoonal surge. The ridge is
likely to weaken late in the weekend and early next with the upper
high forecast to shift from west of the Four Corners to southern New
Mexico and southwest Texas. The magnitude and duration of the
monsoonal moisture across the West Coast and central Intermountain
West remains uncertain beyond this weekend, especially with the
uncertainty of the upper-level pattern over the West Coast and
northern Intermountain West early to mid next week.

...Day 3/Friday...
Isolated to scattered mixed wet/dry thunderstorms are likely from
the West Slope across the southern/central Great Basin onto the
eastern slopes of the southern/central Sierra on Day 3/Friday. Two
10% areas were introduced in areas where drier thunderstorms are
most likely to overlap receptive fuels. Wetter storms are more
likely across Utah into western Colorado, which precluded expanding
the 10% areas at this time. However, it is expected these areas will
be refined in the next 48 hours as more high-resolution forecast
guidance becomes available.

Isolated thunderstorms are likely in portions of southern California
along eastern/northern slopes of the Peninsular Ranges, over the
Mojave, and possibly into the Transverse Ranges. Wetter storms are
likely as PWAT values are over 1" and dewpoints increase into the
40s and possibly low 50s, but cloud bases are likely to be over 3-km
with a hot/dry sub-cloud layer. Isolated high-based showers and
thunderstorms are also possible overnight over the Coast Ranges of
southern California.

For the West, hot/dry/unstable/locally breezy conditions are likely
away from the deeper monsoonal moisture, especially with the West
Coast thermal trough establishing from southern California through
western Washington. Dry and breezy conditions are likely in portions
of New England as Hurricane Erin passes offshore. Breezy northerly
winds amid RH below 40% are likely which may result in elevated
conditions, especially in Maine where the driest fuels appear to be.

...Day 4/Saturday - Day 6/Monday...
Isolated drier thunderstorms are likely in northeast California,
northwest/northeast Nevada, and south-central Oregon on Day
4/Saturday. Thunderstorms chances expand northward farther into
Oregon and possibly into Washington on Day 5/Sunday - Day 6/Monday.
These storms are likely to be a mix of wet/dry, but too much
forecast uncertainty exists to include probabilities beyond Day
4/Saturday at this time. Farther south, wetter thunderstorms are
expected across the Great Basin into Colorado. However, how far
north the deeper monsoonal moisture extends remains uncertainty with
possibly I-80 or Highway 50 serving as potential dividing lines.

Hot, dry, and unstable conditions will continue ahead/along the
leading edge of the monsoonal moisture across the West. The thermal
trough will continue to be a focus point for these conditions
through the weekend.

..Nauslar.. 08/20/2025

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

$$