834
FNUS21 KWNS 070649
FWDDY1

Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0148 AM CDT Mon Sep 07 2026

Valid 071200Z - 081200Z

...Synopsis...
Strong southwesterly flow aloft will overspread the northern Plains
today as an mid-level shortwave trough traverses northeastward
across the northern Rockies and into south-central Canada.
Simultaneously, a surface cyclone currently analyzed in southeastern
Montana will strengthen as it lifts northeastward into the southern
Canadian Prairies, resulting in a tightened surface pressure
gradient across the region. While slightly cooler daytime
temperatures will prevail, windy conditions spurred by the
strengthening pressure gradient will foster elevated fire weather
concerns across portions of the northern/eastern Wyoming, southern
Montana, and the Black Hills vicinity.

...Southern Montana into northern/eastern Wyoming and the Black
Hills vicinity...
The aforementioned strengthening surface pressure gradient will
encourage sustained surface winds to strengthen to 15-25 mph across
the northern High Plains. An overlapping 30-40 kt 700 mb jet will
also translate eastward through the afternoon, with deep boundary
layer mixing encouraging 30-40 mph wind gusts to reach the surface
(perhaps up to 50 mph in terrain favored areas and along exposed
areas of higher elevation). While minimum RH values are only
forecast in the 15-25% range, fuels across the area are commonly
above the 80-90th percentiles. This overlap of strong surface winds,
modest minimum RH, and receptive fuels will support an elevated fire
weather threat across the region today. While widespread critical
conditions appear unlikely at this time owing to only modest RH
reductions, locally critical conditions may be possible should lower
minimum RH values materialize.

Of further note, a trailing cold front will extend southwestward
from the strengthening surface low. The passage of this front
through the region will yield a shift from generally westerly winds
to northwesterly. While some uncertainty remains regarding the exact
timing of the frontal passage, current guidance suggests the front
will extend southwestward from near the MT/ND/SD border by 18 UTC,
with the shift to northwesterly winds gradually spreading farther
southeastward after 00 UTC Tuesday as the front begins to
accelerate; although, wind speeds should largely weaken by around
03-06 UTC.

..Chalmers.. 09/07/2026

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

$$