


Fire Weather Outlook Discussion
Issued by NWS
Issued by NWS
642 FNUS22 KWNS 171943 FWDDY2 Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0242 PM CDT Sun Aug 17 2025 Valid 181200Z - 191200Z ...NO CRITICAL AREAS... ...Northern Rockies/Central Idaho Mountains... A mid-level trough over the Pacific Northwest, residual Pacific/monsoon moisture and daytime heating will result in isolated showers and thunderstorms across northern ID and higher terrain of western MT. Although northeast thunderstorm motions of 25-30 knots will limit rainfall, fuels remain mostly non-receptive to new lightning ignitions across the Northern Rockies, precluding introduction of dry thunderstorm highlights for Monday. ...Great Basin... Modest south-southwest deep layer flow and efficient daytime mixing of a deep/dry boundary layer will support sustained south-southwest winds of 10-15 mph across southern/northern NV Monday afternoon, mainly in longitudinal oriented valleys. Winds combined with relative humidity nearing 10 percent will support short duration and localized elevated fire weather conditions across southern, central and northeastern NV where very dry fuels exist. ..Williams.. 08/17/2025 .PREV DISCUSSION... /ISSUED 0201 AM CDT Sun Aug 17 2025/ ...Synopsis... Mid-level ridging will rapidly build over the central and western US Monday as Northwest troughing continues. Above normal temperatures are expected along with a temporary decrease in monsoon moisture over much of the West. While the ridge expands, the majority of the stronger westerly flow will be shunted northward, poorly overlapping with the expected dry conditions. With weaker flow aloft, surface winds are expected to be relatively benign, limiting fire-weather potential. Still, very hot and dry conditions are expected, which could exacerbate ongoing fires locally. Additionally, a few thunderstorms remain possible over parts of eastern ID and western MT near the periphery of the ridge. While some dry lightning strikes are possible in receptive fuels, wetting rainfall and the more limited storm coverage appear unlikely to warrant 10% IsoDryT coverage. ...Please see www.spc.noaa.gov/fire for graphic product... $$