National Weather Service forecast offices issued red-flag warnings for parts of eastern Washington and for the Reno/Sierra region for Saturday, August 22. NWS Seattle posted a warning issued August 21 that remained in effect until August 22 at 5:00 PM PDT for eastern Washington zones, citing high-based showers and thunderstorms, widespread breezy westerly winds, and low relative humidity. NWS Pendleton issued a red-flag warning August 21 valid through August 22 at 11:00 PM PDT covering zones including the Washington Cascades and Okanogan Valley. Forecast office REV continued a red-flag warning valid August 22, and OTX and SEW listed multiple eastern Washington forecast zones and mountain slopes above 1500 feet under warning conditions. Several regional offices updated watches overnight; MFR canceled some warnings for Modoc County and Klamath Basin while BOI and PIH maintained warnings for portions of Idaho and eastern Oregon. The combination of thunderstorms, gusty winds, and low humidity raises the immediate risk of rapid wildfire spread and will affect firefighting posture and local outdoor fire restrictions through August 22.
