A dangerous combination of dry and breezy conditions, low relative humidity, and lightning-producing thunderstorms is creating critical fire weather across Oregon, Washington, and the broader Intermountain West this week. The National Weather Service Pendleton office has issued multiple red flag warnings covering parts of southern and eastern Oregon, and forecasters warn that the pattern is expected to persist through mid-week.

Red Flag Warnings

The NWS Pendleton office issued a red flag warning for Fire Weather Zones covering the Lower Columbia Basin of Oregon on July 6 and again on July 7, valid through the evening hours. The warnings cited dry and breezy to windy conditions leading to critical fire weather during afternoon and evening periods. Red flag warnings mean that any fire that ignites will catch and spread rapidly — outdoor burning is strongly discouraged during warning periods.

Southern and eastern Oregon also saw red flag warnings on July 6. Parts of northern Oregon and central eastern Washington were under red flag conditions on July 4, when gusts in the Columbia River Gorge and Kittitas Valley reached up to 40 mph. Those conditions on the Fourth of July directly contributed to ignitions including the Chelan Hills Fire and the Antelope Creek Fire.

Thunderstorm Threat

Isolated to locally scattered mixed wet and dry thunderstorms are expected to continue developing across eastern Oregon into the northern and eastern Great Basin and much of the Rockies. "Dry" thunderstorms — those that produce lightning but little or no rain reaching the ground — are a particularly dangerous ignition source in drought-stressed terrain.

According to NIFC, outflow winds from thunderstorm cells can gust up to 50 mph, which can cause existing fires to make sudden, rapid runs and can complicate aerial firefighting operations. The threat of multiple new ignitions from lightning strikes is elevated across the entire region through at least Thursday.

Fuels and Drought

Fine fuels — grasses, shrubs, and light brush — across eastern Oregon, eastern Washington, and southern Idaho are critically dry following a below-average spring precipitation season. Relative humidity across the Intermountain West is dropping to 10–25% during afternoon hours, well below the threshold for critical fire behavior. The combination of cured fine fuels, low humidity, and wind creates conditions where small fires can become large ones within hours.

What Residents Should Do

  • Avoid all outdoor burning, including campfires, during red flag warning periods.
  • Do not park or drive vehicles on dry grass — exhaust systems can ignite vegetation.
  • Keep defensible space clear around structures.
  • Have an evacuation plan ready and know your local evacuation zone level.
  • Monitor the NWS Pendleton and NWS Seattle offices for updated fire weather watches and warnings.
  • Check InciWeb and your county sheriff's office for active evacuation orders.

Forecast Outlook

Breezy west to southwest winds are expected to persist along the east slopes of the Cascades to the Sierra Front, creating areas of elevated fire conditions even outside of red flag warning zones. Fire managers across the Northwest are urging extreme caution and vigilance from all residents and visitors to the region through at least the end of this week.