Note: Some users might notice intermittent discrepancies in colors shown on the map of air quality monitors above, and those reported on the Department of Ecology's official page. This is because Ecology believes their method of calculating the air quality category (i.e. “Good”, “Moderate”, Unhealthy” etc) is more protective of public health in Washington. If in doubt as to which better represents public health risk, use the more stringent of the two (i.e. the map showing worse air quality).
Monday, July 31, 2017
Statewide air quality is mostly Good at present, except for the Methow valley and Darrington. Previous forecast for the Methow is expected to remain valid for the next few days.
Smoke from the Suiattle fire has caused air in Darrington to degrade to Unhealthy for Sensitive Groups. Some relief is expected during the daytime hours today but smoke will likely remain trapped in the valleys overnight and worsen when the morning inversion breaks. Air quality is expected to vary between Moderate and Unhealthy over the next few days, depending on fire activity.
The big story is that the north winds are transporting smoke from British Columbia wildfires into northern Washington. Satellites show that large plumes have already crossed the northern border and will likely impact communities in Okanogan and Whatcom counties between now and Wednesday. Expect air quality to vary between Good and Unhealthy for Sensitive Groups. Some models (see forward trajectories at different heights) suggest this smoke could push all the way down to King County by late Tuesday. We will be watching this closely.
Forecast models show smoke draining further into central WA by mid- week, so communities along the Okanogan river valley should brace for Moderate or poorer air.
Please take a look at the "Smoke and Health" section of this blog, which provides several resources to protect yourself from the harmful effects of smoke.
On the bright side, smoke plumes that remain aloft will offer a little relief from the oppressive heat by providing a thin sun shield that lowers temperatures a degree or two. And they will cause pretty sunsets.
Winds turn easterly from Wednesday onward and while this might reduce the BC smoke faucet, it will likely transport smoke from western Montana to eastern Washington. More on this in the next update.
Friday, July 28, 2017
While smoke drained into the Methow as expected, the amount of smoke was an unpleasant surprise. Air quality in Winthrop has been Unhealthy since midnight and Twisp quickly caught up when the morning inversion broke. Expect some gradual improvement during the day, but not hopeful it will get any better than Moderate today.
A repeat of last night and this morning beckons on Friday and Saturday nights into the following morning, because winds will be terrain- driven each day. Slightly stronger winds on Sunday will help disperse the smoke, leading to Good to Moderate AQ in the Methow.
Thursday, July 27, 2017
If the Diamond Creek fire continues to produce smoke, winds are very likely to keep the Methow Valley somewhat smoky. Here's a snapshot of what we call 'ensemble forward trajectories': it shows how air masses at different heights are likely to travel forward from a certain location. Starting at 11PM tonight, air upto about 1500 feet is likely to drain via the Methow valley over the next 12 hours, bringing smoke from the fire down to ground level. The "ensemble" part refers to how different forecast models characterize the same scenario. The colored lines represent the means of all such models for each release height.
Good consensus that the Methow lies downwind of the fire tonight. Expect Moderate air at night and mostly Good as the day progresses. If smoke is released above 1500 ft, it is possible that some could circle around and mix down when the temperature inversion breaks in the morning. This could lead to Moderate air around Omak and Okanogan, with gradual improvement during the day.
Weekend and beyond are shaping up to be hot with light winds. Here's a snapshot of an ultra-cool animation of temperatures and winds at 2500 ft on Sunday afternoon (not much different to Saturday).
Smoke impacts over the weekend will depend on fire activity. If the status quo persists, the above forecast should be good through Monday.
Monday, July 24, 2017
While strong winds blow away the smoke, they have their own agenda:
Some forecast models suggest Canadian wildfire smoke will get caught up in the northerly winds tonight. Winds are expected to shift to the east briefly, bringing this smoke perilously close to the Cascade crest. But this flow pattern is unlikely to persist for long enough to push smoke into western WA. Neither are they likely to blow smoke from fires in western Montana, all the way to far eastern Washington.
Tuesday should see a lighter winds so smoke impacts will be mostly near the fires. Expect Good air statewide with a few areas of Moderate overnight into Wednesday.
Tuesday, July 18, 2017
Some news on the fires here:
Here's the satellite picture from Monday afternoon. White streaks are clouds, light grey patches are smoke and red dots are fire locations.
Not expecting a strong wind shift through Wednesday evening, so northern WA should continue to see more of the same today, although smoke in northern Whatcom county could start clearing sooner. Air quality in many communities of northern Okanogan, Ferry, Stevens and Pend Oreille could degrade to Unhealthy levels today and tomorrow. Some marginal relief is possible in a few areas tonight.
Winds pick up and change direction by Wednesday night but this is a mixed blessing because it brings the risk of dry lightning, which could mean new wildfires. A Red Flag Warning has been issued to address this. Blowing dust on Thursday morning is likely across the Columbia Basin.
Monday, July 17, 2017
The NOAA HMS Fire and Smoke satellite image shows light smoke from Canadian and Alaskan wildfires over Washington state, but most of it remains aloft. Not expecting strong downward mixing this week so very unlikely that we'll have to inhale much of it. And no, it wont be dense enough to cause spectacular sunsets.
Light north winds are expected across the Columbia Basin today, meaning smoke is likely to drift into the basin. Winds will be driven by daytime heating/ nighttime cooling through Wednesday so not expecting smoke to travel very far from its original sources. Air quality should be mostly Good statewide, except close to fires when periods of Moderate and USG can be expected overnight, with some clearing during the day.
Wednesday, July 12, 2017
Tuesday, July 11, 2017
The fire in British Columbia mentioned in the previous post continues to be the culprit, with smoke mixing to the surface when the overnight temperature inversion breaks. The satellite picture this morning shows smoke pouring down the Okanogan river valley.
Air quality in the area is expected to vary between Moderate and Unhealthy in the area with a slow improvement over the rest of today. Winds are expected to shift to the southwest and help return the smoke back to Canada with a "no thank you" note. But smoke lodged in more sheltered valleys might have a harder time getting scrubbed out, so expect areas of Moderate to USG to persist until tomorrow.
Rest of the state should see mostly Good air for the next few days, except close to some fires where Moderate or USG conditions can be expected during overnight hours.
Saturday, July 8, 2017
The fine particle pollution monitor in Omak bears out the evidence most prominently. Notice how levels spiked over the last 3 mornings.
This happens when (1) northwest flows overnight transport smoke into the area via the Okan(a)ogan river valley, followed by (2) the inversion layer breaking up as the morning sun heats the ground, and (3) smoke aloft mixes to the surface. But daytime winds switch to the southwest and help dissipate smoke- albeit slowly.
Expect another round of the same smoke behavior in the north central counties from Sunday to Tuesday. Periods of Moderate and USG air are likely during the overnight and morning hours. Unhealthy air in communities such as Oroville and Tonasket cannot be ruled out.
And finally, be prepared for more fire concerns on Sunday, followed by a progressively hotter work week.
Friday, July 7, 2017
Of immediate concern is the Red Flag Warning for much of eastern WA today. This graphic from the National Weather Service says it all:
A fair amount of fuels in WA are dry enough to burn, as indicated by the FPI index below (OK nothing like the desert southwest!)
While stronger winds will transport smoke from fires around the Cascade Foothills to parts of the Columbia Basin, fine particle pollution (PM2.5) is likely to be somewhat dispersed and I dont expect air quality to degrade much worse than Moderate later today. However as winds lighten over the weekend, communities such as Wenatchee, Quincy and Sunnyside could potentially see a few hours of Unhealthy for Sensitive Groups (USG) air, mostly at night and early morning. Expect mostly Good to Moderate air in other areas of eastern Washington.
No major storms or winds are expected over the next week. Temperatures are expected to remain close to or just above normal. Firefighting isnt going to be easy so lets do our best to prevent fires.
Wednesday, July 5, 2017
Pollution levels are still dissipating and we expect Good air quality to return later today.
Smoke from any new fires that started in the last day, whether due to fireworks or other reasons, will likely be confined to nearby areas as winds are expected to remain light until about Thursday evening. Expect mostly Good air quality statewide, with a few Moderate periods.
Monday, July 3, 2017
Smoke from fires east and west of Yakima is expected to blow across the central and northeastern Columbia Basin today but air quality is expected to remain mostly Good, except right by the fires where Moderate or Unhealthy for Sensitive Groups can occur overnight.
As winds die down and temperatures ramp up on and after the 4th of July, smoke from existing and new fires is likely to linger in the area. Some cities in Yakima county could see Moderate or USG conditions at times.
No major smoke concerns are expected in western Washington over this period. Have a safe and happy 4th of July!