Statewide Smoke Forecast through Thanksgiving Weekend

Forecast Issued: Nov. 16, 2018 
Forecaster: James Miller, USDA Forest Service

Overall, air quality across Oregon has either improved slightly or remained unchanged compared to yesterday morning. Locations in the Portland to Eugene corridor have experienced slight improvement, but still remain in the moderate air quality category. The most improvement has been within the Portland metro area, where several locations experienced unhealthy for sensitive groups air quality yesterday morning whereas good to moderate conditions were in place this morning. 

Figure 1. The Air Quality Index at 8 a.m. on Friday, November 16, 2018.  

For the rest of today, favorable low-level winds and upper-level atmospheric conditions from a passing weak-weather disturbance should lead to continued air quality improvement in the Willamette Valley, with good to moderate air quality expected in more locations by tomorrow.

Improved atmospheric mixing will also likely produce slight air quality improvement for most of the state by tomorrow, but high-pressure generally remains in place over the region through early next week, so air quality improvements may be short-lived, especially in Central and Southern Oregon. As a result, the Oregon Department of Environmental Quality extended an air stagnation advisory for Southern Oregon through Tuesday in addition to issuing a new advisory for Central Oregon that will be in place from Sunday through Wednesday.

Mid to upper level winds may also introduce smoke from California wildfires into southern portions of the state early next week. The return to weak low-level winds in central and Southern Oregon following a brief improvement in atmospheric mixing this afternoon through tomorrow will trap wood stove and wildfire smoke within valley locations.

However, at this time, we do not expect California wildfire smoke to impact Northern Oregon early next week, so air quality in the good to no worse than the moderate category is anticipated through midweek in the Willamette Valley.

Widespread good air quality should prevail by Thanksgiving into the post-holiday weekend as a more progressive weather pattern develops, bringing a chance of rain and mountain snow for most of the state.

Figure 2. Near-surface smoke forecast from the AIRPACT-5 model for Friday, Nov. 16, 2018 at 6 p.m.

Figure 3. Near-surface smoke forecast from the AIRPACT-5 model for Saturday, Nov. 17, 2018 at noon.

News Release: DEQ extends air quality advisory for smoke impacts

Statewide, Ore.—The Oregon Department of Environmental Quality is extending an air stagnation advisory for Southern Oregon through Tuesday. It is also issuing a new advisory for Central Oregon that will be in place from Sunday through Wednesday.

Air quality in Southern Oregon is expected to improve slightly on Saturday before deteriorating early next week, according to the National Weather Service. Wind could bring smoke from fires in California into Southern Oregon early next week creating hazy conditions. Much of the smoke currently in the state is from local sources such as wood stoves.

The advisory for Southern Oregon covers Douglas, Jackson, Josephine, Klamath and Lake counties. The valleys in Coos County will also be under the advisory beginning at 4 p.m. on Saturday when breezes diminish and conditions become more stagnant.

In Central Oregon, the advisory that starts Sunday covers Umatilla, Morrow, Gilliam, Sherman, Wasco, Jefferson, Deschutes, Crook and Wheeler counties.

Local smoke levels can rise and fall rapidly, depending on fires and weather conditions including wind direction. Residents can view current air quality conditions at DEQ’s Air Quality Index https://oraqi.deq.state.or.us/home/map or by downloading the OregonAir app on smartphones.

Many local jurisdictions are under wood burning restrictions, limiting the use of wood stoves, fireplaces and outdoor fire pits. There are often exceptions for those who use wood exclusively to heat their homes and those with limited income. Check with your local heath or air agency for current restrictions.

The Oregon Health Authority urges residents of affected communities to take steps to avoid health problems during smoky conditions, including:

•      Avoid strenuous outdoor activities when air quality is unhealthy.
•      Those with heart or lung problems, as well as young children, are especially vulnerable.
•      These people should stay indoors while smoke levels are high.
•      True high efficiency particulate air (HEPA) and non-ozone producing electrostatic precipitator (ESP) air cleaners and filters can help keep indoor air cleaner.

Statewide Smoke Forecast through Friday Nov. 16, 2018

Forecast issued: Nov. 15, 2018
Forecaster: James Miller, USDA Forest Service

Air quality across Oregon has been impaired over the past 24 to 36 hours. The smoke is from local sources such as wood stoves and from wildfire smoke from fires burning in California. Determining the exact source can be tricky. As of 11 a.m. on Thursday, Nov. 15, 2018, about three-quarters of the air quality monitoring sites across Oregon were reporting moderate air quality, including most of the Willamette Valley from Eugene north to Portland, most of Southern Oregon from Medford east to Lakeview and Burns, and the Bend area east into the Blue Mountains region. Pockets of unhealthy air quality were reported at six locations, including Baker City, Cave Junction, Salem, parts of metro Portland and Roseburg. Only about 10 percent of monitoring sites were reporting good air quality.

Figure 1. The Air Quality Index at 11 a.m. on Thursday, Nov. 15, 2018.  See the map above for current conditions.

The first question one might ask is, “Why are we seeing widespread smoke impacts in mid-November here in Oregon?” It’s not all from fires burning in the state, rather our air quality is currently impaired partly by smoke from the devastating Camp Fire burning in northern California. High pressure centered over the Intermountain West created off-shore (northeasterly to easterly winds) across much of southern to central California. During the late night hours on Tuesday and early morning hours on Wednesday, winds along the northern California coast and up through Oregon were from the south/southwest, bringing the wildfire smoke from interior California into Oregon. The shorter days of November coupled with the lower sun angle reduce the amount of atmospheric mixing we get in the daytime, thus smoke that infiltrates into valley locations can be stubborn to clear out, as we’ve seen over the past 24 to 36 hours.

Figure 2. Winds at the 850 mb level (approximately 1 mile above the surface) across the western United States on Tuesday, Nov. 13, 2018 at 4 p.m. were from the east and northeast across southern to central California. Winds along the Pacific coastline were mainly from the south to southwest, as indicated by the large red arrows. This weather pattern allowed smoke from California to transport north into Oregon throughout the late night hours on Tuesday into the morning hours on Wednesday.

The next question one might have is, “When will the smoke clear out?” This is a challenging one to answer definitively because much of it depends on the lower to mid-level wind patterns that develop over the next 24 to 48 hours coupled with how much afternoon mixing each specific valley location receives. Based on the smoke and weather forecast models, air quality will generally remain in the moderate category throughout the state through at least Friday afternoon. Late in the day on Friday, an Arctic high pressure system will slide down the eastern slopes of the Rocky Mountains and should produce easterly to northeasterly winds for most of the state which we believe will help scour out the smoke that’s settled into many valley locations. Thus, air quality should begin to improve late in the day on Friday into Saturday morning, though smoke impacts from Pendleton to Baker City and in southwestern Oregon may persist longer than in the Willamette Valley. A key uncertainty is how strong the low-level wind flow will be in more sheltered valley locations.

Figure 3. Near-surface smoke forecast from the AIRPACT-5 model for Friday, Nov. 16, 2018 at 6 a.m.

Figure 4. Near-surface smoke forecast from the AIRPACT-5 model for Friday, Nov.16, 2018 at noon. Smoke impacts are expected to continue through Friday afternoon, especially in western valley locations.

Smoke Outlook Update for Northwest California Natchez Fires for Monday and Tuesday, Oct 1-2, 2018

View a version of the outlook with live links at: https://www.wildlandfiresmoke.net/outlooks/NWCalifornia

Pronóstico de Humo para 01/10 – 02/10 Suroeste de Oregon – Fuegos Klondike y Taylor Creek

View English forecast here

Smoke Outlook Update for Southwest Taylor Creek and Klondike Fires for Monday and Tuesday Oct. 1-2, 2018

Pronóstico de Humo para 30/09 – 01/10 Suroeste de Oregon – Fuegos Klondike y Taylor Creek

View English version here