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Statewide Smoke Forecast for Monday Afternoon Through Wednesday (Aug. 20-23, 2018)

Forecast Issued:  Aug. 20, 2018
Forecaster:  James Miller, USDA Forest Service

The Air Quality Index at 8 a.m. on Monday, Aug.20, 2018.  See the map above for current conditions.


  • Smoky conditions have returned to Northern Oregon, including at the coast, in the Willamette Valley from Portland to Eugene, and throughout Northeastern Oregon.
  • Air quality in Northern Oregon is expected to worsen throughout the day Monday and into Tuesday as north to northeast flow brings in smoke from fires in British Columbia and Washington.
  • Conditions in the northern part of the state will begin to improve Wednesday as a short-wave trough approaches the coast bringing a marine push and westerly winds aloft.
  • There was a slight improvement to air quality in Southern Oregon Sunday night into Monday morning due to easterly winds moving the smoke out to the Pacific Ocean.
  • Southern Oregon air quality will deteriorate throughout the day Monday into Tuesday due to smoke from local wildfires and those to the north impacting the region.
  • In summary, there will be widespread and major air quality impacts across the entire state of Oregon for the next 48 hours.
As of 8 a.m. on Monday, Aug. 20, 2018, moderate air quality conditions were widespread in the Willamette Valley from Portland to Eugene while unhealthy for sensitive groups or worse air quality was prevalent across Eastern Oregon. The poor visibility and air quality in Northern Oregon can be seen in the late morning web cam images from the U.S. Forest Service’s Columbia Gorge (CORI1) and Mount Hood (MOHO2) IMPROVE air quality monitoring locations.

View west from the Columbia Gorge IMPROVE air quality monitor near Wishram, WA at 10:45 a.m. on Monday, August 20, 2018. Current images are available at:

View south from the Mount Hood IMPROVE air quality monitor near Government Camp, OR at 10:45 a.m. on Monday, August 20, 2018. Current images are available at:

As winds shift to northerly to northeasterly across the state, smoke from fires burning to our north in British Columbia and Washington will lead to rapidly declining air quality for most of the state of Oregon on Monday into Tuesday.

The introduction of smoke from fires to the north will produce unhealthy for sensitive groups or unhealthy air quality levels throughout Northern Oregon, including the Willamette Valley where air quality alerts have been issued by the Oregon Department of Environmental Quality through noon on Wednesday. Unhealthy to very unhealthy air quality levels should also be expected in Northeastern, Central, and Southern Oregon on Monday and Tuesday with localized hazardous air quality indices possible.

Air quality should begin to improve in Northern Oregon by Wednesday morning as marine air moves into the region in association with a shortwave trough approaching the coast. Until that time, residents and visitors to the state of Oregon region should limit outdoor activities and stay tuned to the latest forecasts for updates. 

Near-surface smoke forecast from the High-Resolution Rapid Refresh (HRRR) Model for Monday, August 20, 2018 at 4 p.m. (top) and Tuesday, Aug. 21, 2018 at 4 p.m. (bottom).