745
FNUS21 KWNS 081637
FWDDY1

Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1136 AM CDT Tue Sep 08 2026

Valid 081700Z - 091200Z

The ongoing forecast remains on track. 16z satellite imagery
portrays showers associated with the ejecting shortwave trough in
north-central Montana, and mostly clear skies across the northern
Plains. RH values have already declined to less than 20% across
central/southeastern Wyoming amid wind gusts of 15-25 mph, as
depicted by 16z surface observations. Despite slightly cooler
daytime temperatures and spotty recent rainfall in far eastern
Wyoming and parts of western South Dakota, the fuelscape remains
quite receptive. Annual ERCs ranging from the 80-95th percentile
span southeastern Montana into central/southeastern Wyoming and
western South Dakota, where several fires have become established
within the landscape just yesterday (such as the Lookout Fire near
Spearfish, SD and the Moonshine fire west of Wheatland, WY).
Elevated fire weather conditions are expected this afternoon as
westerly winds of 15-20 mph coincide with RH values of 10-20%. A
wind shift from west to northwesterly will occur this evening as a
cold front passes through the area after 00z, with strong wind gusts
of 25-35 mph trailing the front, potentially impacting new/ongoing
fires across the region.

..Elizalde-Garcia.. 09/08/2026

.PREV DISCUSSION... /ISSUED 1255 AM CDT Tue Sep 08 2026/

...Synopsis...
A trailing upper-level wave and associated stronger mid-level flow
will move into the Northern Rockies and northern High Plains through
today as another upper trough accelerates eastward into the Great
Lakes. At the surface, a cold front extending southwestward from a
deep low pressure in Manitoba Canada will push through the Northern
Plains. As a result, the tighter pressure gradient across the
northern High Plains will bolster westerly surface winds over much
of northern/eastern WY as well as portions of southwestern SD, the
NE Panhandle and southeastern MT. These winds along with a dry air
mass augmented by downslope trajectories will support an elevated
fire weather threat today.

...Southeastern Montana into northern/eastern Wyoming and the Black
Hills vicinity...
A 50-60 knot mid-level jet at the base of an approaching short wave
will overspread much of southeastern MT, eastern WY and adjacent
northern Plains later today as westerly winds at the surface are
aided by a lingering modest pressure gradient. Minimum daytime RH of
10-20% will be concentrated in central/northeastern WY with late day
cloud cover infiltrating into southern MT ahead of an advancing
secondary cold front, limiting RH reductions along and north of the
MT/WY border. Although temperatures will be a few degrees cooler
than Monday, the deep layer west-southwest flow and well-mixed
boundary layer should still promote west winds of 15-20 mph by
mid-afternoon. These winds and low RH coincident with dry fuels will
support elevated fire weather concerns across southeastern Montana,
northern/eastern Wyoming and the Black Hills areas. The daytime
westerly winds along with an early/late evening northwest wind shift
could also impact active wildfires within this region.

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

$$