Skip to main content

Statewide Smoke Forecast for Wednesday and Thursday Aug. 22-23, 2018

The Air Quality Index at 9 a.m. on Wednesday, Aug. 22, 2018.  See the map above for current conditions.
Forecast issued: Aug. 22, 2018
Forecaster: James Miller, USDA Forest Service

Air quality across Oregon improved in the past 24 hours with the exception of Southern Oregon where unhealthy conditions remain. On Wednesday morning, air quality at all but one location in the Portland metro area was reporting unhealthy for sensitive groups, a slight improvement over the widespread unhealthy air quality indices on Tuesday morning. Moderate air quality indices were observed throughout Northeastern Oregon Wednesday morning, whereas many locations reported unhealthy conditions yesterday morning. A similar improvement was observed in Bend and Eugene.

For the remainder of Wednesday, the latest smoke models agree that conditions will continue to improve in the Willamette Valley and along the coast. However, the westerly winds aloft leading to improved air quality for Northwestern Oregon will push smoke towards Central and Northeastern Oregon on Wednesday afternoon. Accordingly, air quality across the Blue Mountains region, including the cities of La Grande and Pendleton may deteriorate from moderate to unhealthy for sensitive groups (or worse) on Wednesday before conditions improve begin to improve later in the day Thursday. Confidence is high that air quality will return to the good category for the major population centers throughout the Willamette Valley by no later than Thursday morning, with earlier improvement possible in the southern reaches of the valley (e.g. Corvallis, Eugene) where the marine air push may bring cleaner, clearer conditions by Wednesday afternoon and evening.

Near-surface smoke forecast from the High-Resolution Rapid Refresh (HRRR) Model for Wednesday, August 22, 2018 at 4 p.m.

Near-surface smoke forecast from the High-Resolution Rapid Refresh (HRRR) Model for Thursday, Aug. 23, 2018 at 4 a.m.

Unfortunately, the latest runs of the High-Resolution Rapid Refresh model suggest that smoke impacts will continue for many locations in Central and Southern Oregon, including Ashland, Bend, Klamath Falls, Lakeview and Medford for at least the next 36 hours.

For Thursday afternoon, the High-Resolution Rapid Refresh model runs suggest a sharp transition between good and degraded air quality along a southwest to northeast oriented line from roughly Port Orford on the coast to near Boardman. Areas north and west of this boundary should expect good air quality by tomorrow afternoon, whereas areas south and east of the boundary will likely continue to experience diminished air quality. Accordingly, air quality indices in the unhealthy for sensitive groups to unhealthy range are expected to remain in Central and Southern Oregon through tomorrow afternoon, with localized pockets of worse air quality possible immediately downwind of the fires burning across the central and southern portions of the state.

Near-surface smoke forecast from the High-Resolution Rapid Refresh (HRRR) Model for Thursday, August 23, 2018 at 4 p.m.
Disclaimer: Forecasting weather, fire behavior, and smoke transport and dispersion is challenging. While we strive to bring you the most up-to-date and accurate forecasts, conditions can and do change rapidly. Please take the appropriate action to protect yourself.