PDS Red Flag Warning Signals Extremely Critical Fire Weather Across Eastern Washington This Weekend

The National Weather Service has issued a rare “Particularly Dangerous Situation” (PDS) Red Flag Warning for a large region of Central and Eastern Washington, flagging conditions that fire meteorologists say are among the most extreme they have documented in the region. The warning covers the Waterville Plateau, Okanogan Valley, Western Columbia Basin, and the Spokane area — precisely the zones where many of Washington’s most destructive fires are already burning.

A PDS designation is exceptionally rare. It is reserved for conditions that meteorologists believe have a high probability of resulting in rapid fire growth and significant loss of life or property. This is the first time the National Weather Service has issued a PDS Red Flag Warning for Eastern Washington.

The Ingredients

Several factors are converging to create near-worst-case fire weather conditions this weekend:

Relative humidity: Dropping to 3–15% during afternoon hours — well below critical thresholds
Poor overnight recovery: Humidity not rebounding enough after sunset, allowing fires to maintain dangerous behavior through the night
Wind gusts: Westerly winds gusting 25–40 mph, strongest through the Cascade Gaps
Temperature: Interior elevations reaching or exceeding 100°F at lower elevations
Fuels: Critically dry grass, brush, and timber across the entire fire-affected region after a hot, dry summer

Extended Burn Periods

One of the most dangerous aspects of the current pattern is the lack of overnight humidity recovery. Under normal late-summer conditions, fires moderate after sunset as humidity rises. In the current pattern, that moderation is not happening — fires are maintaining extreme behavior around the clock.

The National Interagency Fire Center noted that “hot, unstable conditions with 3–15% RH and poor overnight recovery will lead to extended burn periods” across the Northwest. This extended activity window dramatically increases the risk of rapid, large-scale fire growth.

Oregonians Also at Risk

Red flag warnings are in effect for north-central Oregon and most of central and eastern Oregon as well, per OPB’s reporting. The conditions on both sides of the Washington-Oregon border are being closely monitored by the Northwest Coordination Center, which is managing resource requests across 50 uncontained large fires in the region.

What You Should Do

Fire managers and emergency officials are urging all residents in Eastern Washington and Oregon to take the following steps immediately:

Avoid any burning, outdoor grilling, or use of equipment that can spark under current conditions
Know your evacuation zone and route before you need it
Sign up for county emergency alerts (Everbridge, ReadySpokane, Ready Chelan, Kittitas County Alert)
Prepare a go-bag: medications, documents, water, chargers, clothing for 3–5 days
Keep vehicles fueled and pointed toward the exit
Monitor NWS Seattle and NWS Spokane forecasts, as well as InciWeb, for rapidly changing conditions

Seasonal Outlook