Washington State Smoke Forecast for Monday -Tuesday September 4-5, 2017

Issued:  Monday September 4 2017

Forecaster.  R. Graw, USDA Forest Service

A high pressure system will remain over the State today producing a subsidence inversion which will hold smoke in the lower parts of the atmosphere today (<10,000 feet).   Above the inversion, westerly winds will transport high levels of smoke and haze across central and eastern Washington.  Below the inversion, easterly winds will transport smoke from the fires in British Columbia, Montana, and Idaho in eastern and central Washington, while smoke from the fires in the Cascades will be transported into the western portions of the state. 

Figure 1 illustrates the overall fire locations (indicated by flames) and smoke pattern at ground level for the state today.   The map is best interpreted in a relative, rather than absolute sense.  The dark red  indicates areas of heavier smoke and the higher shades of red (i.e., pink) indicate areas of lighter smoke.  Because these are 24-hour averages, there will be differences at any given hour.  Some locations may experience heavier concentrations of smoke for shorter durations such as in low-lying area where smoke from the fires drains down valleys.  

Smoke will likely start moving into the Seattle and surrounding metropolitan areas, and eastern portions of the State by early afternoon and will get more concentrated overnight with the onset of the evening temperature inversion, which will hold smoke closer to the ground.  

Figure 1.  Model-Predicted 24-hour Smoke Concentrations for Washington on Monday September 4, 2017

Tuesday, September 5, 2017

Conditions remain much the same as Monday, except the thermal trough will strengthen throughout the day.  Fire activity will likely increase due to the thermal through, but also be tempered by the smoke. East winds underneath the subsidence inversion will persist through the day on Tuesday.  Much of the state will continue experience smoke and haze, very similar to Monday’s forecasted pattern. 

Disclaimer:  Weather and fire activity can change quickly.  Please check back for updates to these forecasts as conditions change.  If you’re traveling out of Washington, many other states also have smoke blogs, including Oregon, Idaho, and California.  So please consider those resources to help you plan your travels.

Expect smoke in western WA Monday- Tuesday; continuous smoke thoughout eastern WA

Note: Many Red flag warnings in effect. PLEASE do your part to prevent fires

Western WA smoke forecast
Some smoke from Oregon showed up from the southwest overnight but for the most part, has remained around 10K ft aloft. Here's a timelapse from Skunk Bay this morning:


Air quality has been mostly Good for the last 24 hours and will likely remain that way for much of Sunday.

There is consensus among models that east winds will start up early Monday morning and persist through Tuesday evening at least. Here are how all the weather models depict relative humidity at SeaTac airport.

The thick black line is the average of them all ("ensemble mean" in geek-speak). Times are in GMT, so subtract 7 hours for local time. When dry air from eastern WA invades, the humidity stays low.

These east winds will transport smoke from the Jolly Mountain fire into the Seattle area, and the Norse Peak fire to southwest WA. There is a chance that smoke from the Diamond Creek and Uno Peak fires could foul up northwest WA. By Tuesday some of this smoke could find its way to the Washington coast. Air quality is likely to vary from Moderate to Unhealthy at different times and places. In general, partial clearing during the day and poor air at night.

Wednesday could bring some short-lived relief as winds shift to south-southwest. Oregon smoke is lurking to our south and could surge into western WA. Hard to win when there is only one "clean" wind direction to work with, i.e. northwest. Please stay tuned.

Eastern WA smoke forecast
Wish I had better news for these folks who have been assailed by wave after wave of smoke. Next several days will to be no different. While east winds starting early Monday reduce smoke transport from Cascades → Columbia Basin, smoke from fires in Idaho and Montana are likely to fill the void and blast far eastern WA.

• Kittitas and Yakima valleys could see a repeat of yesterday, with Unhealthy air gradually improving later in the day Sunday & Monday
• Far eastern WA and the Methow valley are unlikely to deteriorate more than Unhealthy for Sensitive Groups today and tomorrow.

We are looking into ways to provide communities with localized and timely information. Please stay tuned as resources are stretched very thin.

Kittias and Yakima county getting hammered with smoke; little improvement expected before Monday

Unfortunately several cities in Yakima and Kittitas counties got slammed with a lot more smoke than expected today. Conditions in Cle Elum and Toppenish were Very Unhealthy this morning, leading to the cancellation of some sporting events.

A colleague sent in this picture of haze-laden skies in Yakima.

Sections of plumes from the Norse Peak appear to have combined with the Jolly Mountain fire plumes and smoked out the Kittitas and Yakima valleys, as seen in this satellite loop. Not much wind in the forecast today & tomorrow to disperse the smoke, so brace for more of the same, namely mostly Unhealthy air throughout most of Kittitas and Yakima counties through Sunday night. Periods of Very Unhealthy or even Hazardous conditions cannot be ruled out. Things should start to improve by Monday morning as northeast winds pick up a little.

Also notice this morning's MODIS satellite image showing Oregon plumes making a two-pronged approach toward southwest and southeast WA, the former using the Pacific route. 

Smoke in the southeastern WA plume could hit the Lewis- Clark valley, Walla Walla and the Tri Cities later today, leading to air that is Unhealthy for Sensitive Groups between now and Sunday evening.

While the Pacific smoke patch isnt much of threat right now, it is a little harder to predict- will have to wait for the smoke models to run on Sunday morning before we know.

Rest of the forecast issued yesterday is mostly on track.

Every1's askin' about da long weekend

Lets take it one day at a time, because conditions won't remain the same everyday. Except near the fires where it will be cruddy all along. This time too, it is smoke from our own WA fires. Here's a picture of the Norse Creek fire plumes near Chinook Pass snapped by a colleague who jetted eastward on Thursday evening. Not pretty! And weather conditions favor more smoke production all weekend.



BC and OR fires are still burning but smoke wont make its way here this weekend.
OK here goes- bear with the details, which are subject to change:

Friday

Area	Air Quality forecast	Notes
All of western WA	Good
Far eastern WA and Cascade foothills of eastern WA	Moderate/ Unhealthy for Sensitive Groups with some improvement during the day	Cle Elum, Naches and the Methow could see Unhealthy air at night. Newport and Metaline Falls should expect USG air.
Columbia Basin	Good/ Moderate

Saturday and Sunday
Winds slacken, some models show light east winds spilling a teeny-weeny bit of smoke over to the south Puget Sound. Lotsa smoke accumulation near the fires.

Area	Air quality forecast	Notes
All of western WA	Mostly Good	Eastern foothills of King, Pierce and Lewis counties could see a few Moderate hours
Far eastern WA and Cascade foothills of eastern WA	Moderate/ Unhealthy for Sensitive Groups	Cle Elum, Naches, Chelan and the Methow could see Unhealthy air or worse. Newport, Metaline Falls, Ellensburg, Yakima, Leavenworth and Wenatchee will likely remain in USG.
Columbia Basin and southeast WA	Good/ Moderate

Monday
Few smoke models go out that far. Best indications (see 2000ft winds predicted by the European weather model below) are that moderate east winds will develop in far eastern and northern WA to disperse locally accumulated smoke. But these east winds will cause some smoke to dam up against the Cascades and bleed across to western WA.

Area	Air quality forecast	Notes
Puget sound lowlands and Lewis county	Good/ Moderate	Seattle, Tacoma and Olympia could see Moderate air by evening
Rest of western WA	Mostly Good
Far eastern WA	Good/ Moderate	Moderate near Newport, Metaline Falls and the Lewis- Clark valley. Good in Spokane
Eastern WA Cascade foothills	Moderate/ USG/ Unhealthy	Mostly Moderate in the Methow, Omak and Chelan. Wenatchee, Leavenworth, Cle Elum, Ellensburg and Yakima could regularly see USG or worse.
Lower Columbia Basin and southeast WA	Good/ Moderate

Wanna get away from the smoke? Cash in on the warm temperatures and abundant sunshine, and head for the Olympic Peninsula or Washington coast. Now through Monday morning should be mostly smoke free. But plan on leaving by Monday afternoon before east winds start to bring some smoke over there.