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Statewide Smoke Forecast for Wednesday and Thursday

The Air Quality Index at 10 a.m. on Wednesday, Aug. 15, 2018.  See the map above for current conditions.
·         Air quality in Northern Oregon improved modestly overnight into Wednesday morning.
·         A trough off the coast will bring stronger onshore flow (westerly winds) for Thursday into Northwestern Oregon leading to improved air quality for Willamette Valley locations.
·         No significant improvement in air quality is expected in Central and Northeastern Oregon for the next 24 to 36 hours.
·         Major air quality impacts will continue throughout Southwestern Oregon through the forecast period.

Despite a modest improvement in air quality throughout Northern Oregon overnight, major air quality impacts were still occurring across the majority of the state at 10 a.m. on Wednesday, Aug.15, 2018. In the north, a marine air push brought some improvement to air quality for the Portland metro area by Wednesday morning. However, moderate to unhealthy air quality levels remain in the metro area. There was also some improvement east of the Cascades from the surface level onshore flow (westerly winds) where air quality was in the unhealthy for sensitive groups level for La Grande, Pendleton, and The Dalles on Wednesday morning compared to unhealthy levels observed yesterday morning. As forecasted yesterday, air quality in the southern Willamette Valley declined overnight with widespread moderate conditions now observed in the Eugene area compared to good levels on Tuesday morning. In Central Oregon, unhealthy for sensitive groups air quality prevailed throughout the Bend area Wednesday morning. In Southern Oregon, where smoke has been persistent for several weeks, air quality deteriorated even more overnight into Wednesday morning with widespread unhealthy air quality indices reported across the region.

For Wednesday, air quality in Northern Oregon should improve slightly throughout the day as westerly winds help scour some of the surface level smoke, particularly in the northern Willamette Valley. The marine air push should also keep coastal locations relatively free of wildfire smoke impacts. However, smoke higher above the surface will likely persist over Western Oregon throughout the day, as south to southwest winds at the mid-levels bring smoke from Southwestern Oregon northward. Accordingly, hazy skies should be expected in the major population centers of Western Oregon despite some modest improvement in surface-level air quality on Wednesday. East of the Cascades, air quality will likely remain in the moderate to unhealthy for sensitive groups level throughout the day on Wednesday for locations such as Bend, Enterprise, John Day, La Grande, Pendleton, and The Dalles. In Southern Oregon, smoke from the Klondike and Taylor Creek fires, as well as those in Northern California, will continue to produce unhealthy conditions for Ashland, Crater Lake, Grants Pass, Klamath Falls, Lakeview and Medford on Wednesday.

On Thursday, there may be a slight improvement in air quality for Southern Oregon, but pollution at the unhealthy for sensitive groups or unhealthy levels is expected to persist. Likewise, conditions throughout Central Oregon are unlikely to improve significantly on Thursday. The biggest improvement in air quality for Thursday should occur in the Willamette Valley with a trough off the coast bringing a stronger marine air push inland.

Near-surface smoke forecast from the High-Resolution Rapid Refresh (HRRR) Model for Wednesday, Aug. 15, 2018 at 4 p.m. (top) and Thursday, Aug. 16, 2018 at 4 p.m. (bottom).
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.