Fire Weather Outlook Discussion
Issued by NWS
Issued by NWS
946 FNUS22 KWNS 250602 FWDDY2 Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0102 AM CDT Tue Aug 25 2026 Valid 261200Z - 271200Z ...Synopsis... An upper-level trough impinging upon the Pacific Northwest will usher in increasing southwesterly flow and dry conditions to portions of the interior Northwest and northern Great Basin. The trough and afternoon destabilization will also bring a dry thunderstorm threat to the portions of the northern Rockies Wednesday afternoon. Farther south, an offshore pressure gradient becomes established this evening and overnight hours leading to fire weather concerns across portions of southern CA. ...Northern Rockies into northern Washington... The upper-level trough nearing the Pacific Northwest will boost southwest flow aloft while residual monsoon moisture lingers across the northern Rockies. Daytime instability over complex topography in addition to diffuse forcing for ascent will likely bring a broad area of isolated high-based showers and thunderstorms to the northern Rockies in western MT and northern ID as well as across northern WA. PWAT values will generally be below 0.80" while a dry, sub-cloud boundary layer and high surface dew point depressions inhibit rainfall accumulations. Fuels remain receptive with new ignitions possible Wednesday afternoon from this thunderstorm activity. ...Columbia Basin southward towards the northern Great Basin and Northeastern California... Increasingly dry southwest flow as deeper monsoon moisture pushes eastward is expected to bring elevated fire weather concerns to much of the Interior Northwest and northern Sierra Nevada Wednesday. An evolving well-mixed and dry boundary layer by peak afternoon heating will support enhanced southwest winds at the surface of around 15 mph. These winds coupled with RH as low as 10 percent amid dry fuels will promote elevated fire weather conditions across the region. A locally critical fire weather concern may emerge across northeastern CA into southeastern OR where sustained southwest winds of 20 mph may occur at times. ...Southern California... A multi-day elevated fire weather threat will continue for portions of southern CA late Wednesday into early Thursday morning as offshore/sundowner winds develop with supportive surface high pressure across the Great Basin. Offshore winds of 15-25 mph are expected in favored terrain and downslope regions as RH falls to as low as 15 percent beginning Wednesday evening into early Thursday morning. Elevated highlights were introduced into portions of LA/Ventura/Santa Barbara counties. ..Williams.. 08/25/2026 ...Please see www.spc.noaa.gov/fire for graphic product... $$