204
FNUS28 KWNS 182123
FWDD38

Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0421 PM CDT Mon Aug 18 2025

Valid 201200Z - 261200Z

An upper-level ridge centered near the Four Corners will break down
over the Northern Rockies Day 3/Wednesday - Day 4/Thursday. A dry
cold front will stall in the northern Great Basin and across
northern Wyoming by Day 4/Thursday with a cold front likely pushing
south down the Plains and into the Southeast late this week and this
weekend. The upper-level ridge is forecast to shift west and build
through the Northwest and northern Rockies late this week and
through the weekend. Monsoonal moisture will move north and west
into the Great Basin, central Rockies, and southern California,
increasing chances of thunderstorms following.

...Day 3/Wednesday: central Great Basin into northern Rockies...
Isolated dry thunderstorms are possible from eastern Nevada into far
southwest Montana and northwest Wyoming on Day 3/Wednesday,
including possibly overnight in eastern Idaho and northwest Wyoming.
Mid-level moisture will increase ahead of the upper-level trough on
the western/northern periphery of the upper high, but uncertainty
remains regarding the coverage and location of high-based
thunderstorms in a corridor from eastern Nevada/western Utah into
southwest Montana and western Wyoming. Hot, dry, and breezy
conditions are also likely across the northern Great Basin with
elevated fire weather conditions possible.

...Day 4/Thursday - Day 8/Monday...
As the ridge builds over much of the West, monsoonal moisture will
continue to push west and north increasing thunderstorm chances
across portions of southern California, the Sierra, Great Basin, and
the Rocky Mountains of Colorado and Wyoming. Forecast uncertainty
remains regarding the magnitude of the monsoonal moisture,
especially regarding the arrival of deeper monsoonal moisture in
portions of the southern/central Intermountain West. High-based,
drier thunderstorms are likely along the periphery and leading edge
of this monsoonal moisture, but too much uncertainty on timing and
location precludes introducing probabilities at this time. Well
above normal temperatures are expected across much of the West, with
low RH ahead of the monsoonal moisture.

..Nauslar.. 08/18/2025

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

$$