Dense Smoke — Upper Columbia Basin, Washington

2020-09-12 to 2020-09-19 · Upper Columbia Basin, Washington

Event narrative

An air quality sensor in Ritzville recorded unhealthy air quality from September 12th through September 19th with spikes into the Very Unhealthy and Hazardous categories. A cold front passage brought showers and westerly winds which ventilated the area.

Wider weather episode

Multiple large wildfires in Washington, Oregon, and surrounding states produced copious quantities of dense smoke throughout the month of September. Due to poor ventilation and a gradual return to southwest winds, there were increasing amounts of wildfire smoke to Washington. The smoke from these fires severely degraded air quality across much of eastern Washington in mid-September. Numerous communities, especially in the Spokane area, suffered long periods of very unhealthy to hazardous air quality.

Source: NOAA Storm Events Database, event_id 922090. Narrative written by the NWS forecast office that issued the report.