Western WA: enjoy the nice sunsets courtesy of CA smoke. Eastern WA: lift up your heads and breathe again, your deliverance is here to stay.

For a week at least.

Deliverance from wildfire smoke, that is. 

Just sayin'.

Time to start playing your favorite songs about clear skies and bright sunshine.

Western WA

An approaching weather system is dragging smoke from northern CA fires over the region and very little is expected to mix down. Don't expect anything worse than Moderate between now and tomorrow, after which everything gets shunted further east. Should have a nice sunset today. 

Eastern WA

Relief commenced on Monday afternoon and yesterday's weather system helped knock back fires even further. Not by just pushing it off to BC, but by mixing it through a deeper layer. Here's a timeseries of all eastern WA fine particle monitors showing how levels dropped starting Monday at sites closest to fires and then more consistently yesterday. This is an 8-hr  running average to smooth out the noise. Mostly Moderate air in eastern WA right now, except some Unhealthy for Sensitive Groups closer to the Methow valley fires. 

Yesterday's thunderstorms did spark off a few new fires. Even they're mostly relatively small, winds tonight are expected to 'fan the flames' so this bears watching. New fire starts are also of concern:

The big change starts Thursday with cooler temperatures, winds and a good deal of wetting rain dumped right on the fires. Post rain, cooler temperatures and good ventilation conditions are expected for several days, so there does not seem to be any imminent danger of returning to what we saw last weekend. Mostly Good to Moderate air and no worse than USG closer to fires.

Ecology's 5-day smoke forecast is currently over-estimating concentrations, and this is an artifact of how certain machine learning models struggle with characterizing big weather transitions. The model solutions are weighted most by the previous day's observed smoke levels. Further, the smoke and cloud cover over the last few days prevented satellites from detecting ongoing fires and this led to an under-estimate of smoke conditions a few days out. These errors don't offset each other. The forecaster community is working to identify solutions to these and other issues, so smoke forecasts will continue to be evolving products. 

Here are the satellite- derived PM_2.5 concentrations for Monday & Tuesday. Notice the data gaps in areas where cloud cover or smoke is obvious. And the stark transition as you cross the Cascades. Mountains holding smoke at bay. 

Smoke and the water

Rain in parts of north-central Washington over the weekend limited fire growth and aided firefighters, but those clouds also kept smoke from the fires near to the ground, leading to very unhealthy and even hazardous air quality readings in many places Monday morning. 

Aug. 2 smoke forecast

Temperatures across much of eastern Washington are headed toward triple digits once again. That will raise the fire danger, but it should also return us to the pattern we’ve seen in recent weeks where smoke settles near the ground overnight, then mixes up into the atmosphere as the heat of the day kicks in.

That daytime dilution won’t be enough to put a permanent dent in the smoke, unfortunately. The Washington Department of Ecology issued an Air Quality Alert for all of Washington east of the Cascade crest through noon Thursday.

What happens at noon Thursday, you ask? A stronger weather system is on the way, bringing rain to many parts of the state and enough wind to really push out the smoke. That new system won’t fully arrive until Friday, but we’ll see the benefits beginning Thursday afternoon. 

Don’t expect too much from this front, though. Although much of eastern Washington will see cleaner air by the weekend, areas near the big fires in Okanogan County will continue to experience localized smoke impacts anywhere from the “unhealthy for sensitive groups” to the “very unhealthy” range. 

Local fire forecasts

Just a reminder that you’ll find regional and statewide forecasts here on the Washington Smoke Blog home page. Smoke forecasts for specific fires where Air Resource Advisors have been assigned are just a click away, under the “Local Smoke Outlooks” tab.

Western WA outlook: Some smoke upstairs, but good on the ground floor…

Western Washington has mostly lucked out so far this year when it comes to wildfire smoke. We can thank a steady flow of clean air from the Pacific Ocean, except for a short visit from that in-law we’re all trying to forget, a certain heat-dome that probably deserves its own name. But I’ll save that for another time.

Anyway, that steady flow of clean air can’t hold up all summer, and indeed it seems to be changing on Friday, Saturday, and into Sunday. The HRRR model shows a decent plume arriving in western Washington late Friday afternoon, with another wave heading in overnight and into Saturday. Here’s some more details:

So far, the Pacific Northwest has mostly been getting clean marine air flowing west to east . But a ripple in the pressure patterns has sent smoke from Northern California and Oregon to the northwest, and right for us. This is forecast to arrive late Friday afternoon. (See the first figure, which shows the sum of smoke at all levels, like looking down from a satellite) The pressure gradient in central and eastern Washington, and further east, will also shift on Friday and Saturday and start sending smoke to us, too. Saturday late afternoon, we’ll get another wave of smoke from central and eastern Washington and British Columbia.   

But what does this mean for Western Washington air quality? … it looks to be a classic upstairs-downstairs situation, in which most of us in the lowlands of Puget Sound and Western Washington will likely be spared, while smoke passes overhead.

While two waves of smoke are expected to reach our skies, they’ll be at 2 km or higher (see the second figure), and the situation at surface should be very different. Over the weekend, there will still be a pressure gradient at the surface from the coast to the western side of the Cascades. So, clean marine should continue to push in, to at least the foothills. Although the upstairs smoke and the downstairs marine air generally keep to themselves, there’s a chance that a few of the upstairs visitors might trickle downstairs and push us to MODERATE air quality.

To add to this mix, the warmer temperatures are bringing us elevated ozone (smog) conditions. The atmosphere cooks up ozone from the emissions of cars, trucks, industry, and even plants. In the summer, when the temperatures get turned up to the 80s and 90s, the ozone can build up to levels that are considered Unhealthy for Sensitive Groups. Because the “cooking” of the urban emissions takes time and the winds during these hot episodes are to the east, the high ozone levels mostly occur in the foothills of the Cascades and not in the urban core. Today (Friday) we’re likely to see highs around 90, which means ozone might reach Unhealthy for Sensitive Groups. Saturday will still be hot, but will have some clouds, so the “cooking” won’t be as fast, so we should stay in the Moderate air quality category, for ozone, and therefore overall… assuming no smoke sneaks down from upstairs.

If the forecast holds, the Puget Sound should continue to have GOOD to MODERATE air quality downstairs, even though the upstairs will look hazy. And, hopefully, we won’t get much lightning in the Cascades.  

Eastern WA smoke and weekend outlook (watch for a Western WA outlook tomorrow)

Spare a thought for our neighbors in Okanogan County who are facing what appears to be the earliest start to smoke season. The plot below shows how fine particle pollution levels have evolved between June and September each year since permanent monitors were established in the county. This year (thick red line) spiked earlier than other years, but thankfully not as high as some previous years which we all prefer to forget.

This morning's satellite picture shows how south winds from yesterday have continued to push the smoke northward. However this upper level wind pattern can only do so much with high pressure building in to the area. 

No doubt the British Columbians love us dearly for all that. 

Good news is that a decent amount of rain is expected in the North Cascades Sunday into Monday, aiding firefighting efforts. But first we've got to get through a scorching weekend with little wind. An Air Quality Alert is in effect for the northern counties. 

Elsewhere in eastern WA

We expect some smoke from Oregon fires to start moving over the Columbia Basin from Friday, causing Moderate air which could later degrade to Unhealthy for Sensitive Groups. Here's a snapshot of all the different forecasts (aka "ensemble models") we have for Spokane and Colville, for the next 5 days. Although there's a wide spread among predictions, Unhealthy air cannot be ruled out. 

Please use the resources on this blog to safeguard your health during smoke events.

Check out the technicalese explanation of our ensemble smoke forecast system here. 

7/27/2021 Smoke Blog Update

We've implemented a minor redesign to the blog and added a new tab for our readers to quickly and easily access the custom smoke forecasts prepared by Air Resource Advisors assigned to incident management teams working in Washington. Notice the new tab along the top border of the blog content area and click on "LOCAL SMOKE OUTLOOKS" to access the forecasts.

Interested in smoke forecasts prepared for other states? You can find the full set of smoke outlooks prepared by Air Resource Advisors at this link: https://wildlandfiresmoke.net/outlooks  

North Central WA Smoke Outlook for 7/26 - 7/27

 

7/26/21 Smoke Outlook for SE Washington - Lick Creek/Green Ridge

A detailed version of this outlook with live links can be found here: https://wildlandfiresmoke.net/outlooks/sewashington 

 *This outlook was produced through the support of the incident management team assigned to the Lick Creek and Green Ridge fires to help inform nearby communities of smoke impacts.

 

Monday, July 26, 2021 - Smoke Outlook for Colville Reservation #ColvilleReservationFires

A detailed version of this Outlook with live links can be found here: https://wildlandfiresmoke.net/outlooks/newashington

*This Outlook was produced through the support of the incident management teams assigned to the Summit Trail and Chuweah Creek fires on the Colville Reservation to help inform nearby communities of smoke impacts.

 

Pronostico de Humo para 25/07 - 26/07 North Central Washington Cedar Ck, Delancy, Cub Creek 2

 

Smoke Outlook for 7/25 - 7/26 North Central Washington