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| The Air Quality Index at 10 a.m. on Wednesday, Aug. 15, 2018. See the map above for current conditions. |
Highlights
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Air quality in
Northern Oregon improved modestly overnight into Wednesday morning.
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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.
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No
significant improvement in air quality is expected in Central and Northeastern
Oregon for the next 24 to 36 hours.
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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.
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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).
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