601
FNUS28 KWNS 082158
FWDD38

Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0456 PM CDT Tue Sep 08 2026

Valid 101200Z - 161200Z

...Synopsis...
A mid-level shortwave trough will descend into the northwestern U.S.
as a surface cyclone traverses the Canadian Prairies on Day
3/Thursday. Strong flow aloft and a tightening surface pressure
gradient will promote widespread dry and breezy conditions across
the northern Great Basin into the northern Plains. A strong cold
front will then navigate the north-central states as the shortwave
trough departs on Day 4/Friday; meanwhile, dry west-southwesterly
flow will overspread the northwestern CONUS. Ensembles are in
general agreement for an upper-level low to invade the Pacific
Northwest and Northern Rockies this weekend. This pattern may
provide broader precipitation chances and much cooler temperatures,
thus subduing fire weather concerns across most of the
northwestern/northern CONUS into early next week.

...Central Rockies into the Northern High Plains...
A dry airmass and strong winds will expand across the northern Great
Basin into the northern Plains on Day 3/Thursday. Westerly sustained
winds of 15-25 mph and 10-20% RH values will increase fire weather
concerns from far eastern ID/southwestern MT into the northern
Plains where 80-95th percentile ERCs exist. Poor overnight humidity
recoveries are forecast across eastern WY, western SD, and the NE
Panhandle leading into a second consecutive day of concern; on Day
4/Friday, RH values will quickly decline to 10-20% as winds
accelerate ahead of an advancing cold front. Sustained westerly
winds may approach 25 mph across the terrain-favored plains, then
shift to northerly as the front passes. Notably, guidance indicates
a 50-80% probability of wind gusts exceeding 35 mph through the
afternoon. 40% Critical probabilities have been introduced on Day
4/Friday across southeastern WY, northwestern NE Panhandle, and
southwestern SD to account for this threat.

...Northeastern California and western Great Basin...
An Eastern Pacific upper low will impinge upon the northwestern U.S.
on Day 5/Saturday, amplifying west-southwesterly flow over northern
CA and the western Great Basin. Ensemble guidance depicts 70-90%
probabilities of wind speeds exceeding 20 mph amid critically low RH
in northeastern CA and northern NV, which would typically enhance
fire weather concerns. However, forecast ERCs at the 50-70th
percentile should mitigate a broader threat.

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

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

$$