The National Weather Service issued a Particularly Dangerous Situation (PDS) Red Flag Warning across large portions of eastern Washington and northeastern Oregon this past weekend — the first such designation in the Pacific Northwest since September 2020. The rare alert, reserved for the most extreme fire weather conditions, underscored a forecast of catastrophic fire potential that ultimately proved accurate.
What Is a PDS Red Flag Warning?
A standard Red Flag Warning already signals critical fire weather: low relative humidity, high temperatures, low fuel moisture, and gusty winds. A Particularly Dangerous Situation upgrade is reserved for events where these factors combine so severely that rapid and explosive fire growth is considered highly likely, and where the potential for life-threatening fire spread is imminent.
The Storm Prediction Center issued an Extreme fire weather outlook — its highest level — for the Columbia Basin and portions of central and eastern Washington into north-central Oregon, where dry downslope flow off the Cascades was forecast to drive relative humidity as low as 15% to 20% while sustained winds increased to 20–30 mph, with gusts exceeding 45 mph.
The Dry Cold Front
Rather than bringing the rain that the fire-weary region desperately needed, a dry cold front swept through the Northwest, delivering powerful gusty winds and sharply lower humidity without meaningful precipitation. These offshore-flow conditions — when air descends from higher elevations and warms and dries as it compresses — are among the most feared fire weather scenarios in the Pacific Northwest.
The most dangerous conditions materialized across the Columbia Basin and central/eastern Washington into north-central Oregon. Fire weather warnings were issued across the broader Northwest in advance of the event.
Impacts Confirmed
The PDS forecast proved accurate. The Old Trails Fire in Spokane exploded to more than 3,500 acres on Saturday afternoon, destroying over 640 structures. Multiple other large fires across eastern Washington and Oregon exhibited extreme fire behavior with wind-driven runs, crowning, and long-range spotting during the high-wind event.
The National Weather Service also issued an Air Quality Alert alongside the fire weather alerts, as smoke from dozens of fires blanketed the region under stagnant atmospheric conditions.
What to Expect This Week
Fire weather conditions are expected to gradually moderate as the cold front fully passes, but the inland Northwest — particularly southeast Oregon — could see continued elevated conditions through early this week. Fuel moisture levels remain critically low after a hot, dry summer, meaning even moderate winds and low humidity could sustain or ignite new fire activity.
Residents across eastern Washington, eastern Oregon, and southern Idaho should remain vigilant. Report new smoke columns immediately by calling 911.