Critical Fire Weather Continues Across Inland Northwest: High Winds, Record Heat, and Dry Lightning

Dangerous fire weather conditions are forecast to persist across the inland Pacific Northwest through the end of August, with the National Interagency Fire Center warning that high-risk significant fire potential remains elevated for the region. A combination of above-normal temperatures, critically low relative humidity, gusty winds, and the threat of dry lightning from isolated thunderstorms is creating a volatile environment for new fire starts and rapid spread of existing blazes.

NIFC Weather Outlook

NIFC's August 26 weather briefing noted that breezy westerly winds with gusts of 25 to 35 mph are developing across the northern half of the West away from the coast, including the inland Pacific Northwest. Relative humidity in the most affected areas is dropping to the 10 to 20 percent range — extreme by any measure — while temperatures are running 10 to 15 degrees Fahrenheit above normal across the region.

The agency describes these combined conditions as bringing "high-risk significant fire potential" to the northern Great Basin, inland Pacific Northwest, and Sierra Front. In plain terms: when a fire starts under these conditions, it is extremely difficult to control.

Dry Lightning: A Growing Threat

Isolated to scattered mixed wet and dry thunderstorms are expected from Idaho into western Montana and the northern Great Basin. Dry thunderstorms — those that produce lightning and thunder but little or no rainfall at the surface — are particularly dangerous because they can simultaneously ignite multiple fires across remote terrain while providing no moisture benefit to fuels. During periods of heavy fire activity, these storms can overwhelm initial attack resources, forcing agencies to triage which ignitions to respond to first.

At National Preparedness Level 5, with 22,356 firefighters already committed to 93 active large fires, the ability to respond to new starts is severely constrained. Fire managers are pre-positioning aircraft and initial attack crews in areas where thunderstorm activity is forecast.

Fuel Conditions

Fuels across the inland Northwest are at critically low moisture levels after a hot, dry summer. The Fuels and Fire Behavior Advisory issued by the Northwest Coordination Center on August 25 flagged extremely dry vegetation across both Oregon and Washington, including fine fuels such as grasses and shrubs that can carry fire at rates of spread measured in miles per hour under windy conditions.

The combination of record drought — which Washington's governor cited in his statewide emergency declaration — and the early onset of summer heat has left the region with fuels that are months ahead of their typical late-season dryness. Fire behavior analysts warn that even modest wind events can produce extreme fire behavior under current conditions.

Red Flag Warning Criteria

The National Weather Service issues Red Flag Warnings when a combination of conditions creates a critical fire weather environment. In the Northwest, these typically require winds gusting above 25 mph, relative humidity below 25 percent, and fine fuel moisture below critical thresholds. When a Particularly Dangerous Situation (PDS) Red Flag Warning is issued — as occurred in eastern Washington on August 1 — it signals that conditions are among the most extreme possible and that rapid, catastrophic fire behavior is likely.

Current RH: 10–20% across interior Northwest
Wind gusts: 25–35 mph forecast
Temperature anomaly: 10–15°F above normal
Lightning risk: Elevated through Idaho and western Montana
NWCC Preparedness Level: 5 (maximum)

What This Means for Residents