672
FNUS28 KWNS 212141
FWDD38

Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0439 PM CDT Tue Jul 21 2026

Valid 231200Z - 291200Z

Upper-level troughing will move into the Pacific Northwest with
stronger southwest to westerly flow aloft across the northwest US
starting Day 3/Thursday and continuing through the weekend. The
upper low will likely remain off the coast until this weekend, but
forecast guidance remains uncertain regarding its track and timing.
An upper high will remain in the vicinity of the Four Corners into
the weekend, with daily monsoonal thunderstorms likely continuing
across the region.

As upper-level troughing begins to move into the Northwest, isolated
to scattered mixed wet/dry thunderstorms are likely across
central/eastern Washington, eastern Oregon, and western/north Idaho
into northwest Montana Day 3/Thursday. Residual subtropical moisture
will maintain PWAT values of 0.75-1.1", but storm motions of 20-30
knots, a dry sub cloud layer, and receptive fuels will result in
lightning ignitions. Dry and breezy conditions will also develop
during the afternoon and evening from central/eastern Washington
extending south into northeast California and northwest Nevada as
the onshore pressure gradient tightens and stronger winds aloft
arrive that can mix to the surface.

With an onshore pressure gradient, surface pressure troughing
extending from eastern Washington to southwest Idaho, and 40-65 knot
mid-level flow, breezy west-southwest winds will develop across the
Inland Northwest, northwest Great Basin, and the northern Rockies
onto the northern Plains Day 4/Friday - Day 5/Saturday and possibly
Day 6/Sunday. Drier air will move across this region as well, with
elevated to locally critical conditions expected. These dry and
breezy conditions will follow lightning likely resulting in
holdovers and growth on existing wildfires, especially active large
wildfires.

Forecast guidance remains mixed on identifying corridors of critical
conditions, which precludes introducing 70% area(s) at this time.
Ensemble forecast guidance (GEFS, ECENS, and NBM) indicates that
critical winds/RH are likely to develop (> 50% probabilities), but
these corridors are somewhat narrow and tend to overlap some of the
areas that have less receptive fuels. However, given the forecast
pattern, BIs, and Hot-Dry-Windy-Index probabilities, critical
conditions will likely develop in portions of the 40% areas on Day
4/Friday - Day 5/Saturday.

..Nauslar.. 07/21/2026

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

$$