August 22, 2018


Marine air is now pouring into western Washington, rapidly replacing the warm and smoky air that has been in place since Sunday.

Wind chimes are ringing, leaves on trees are rustling, window shades are banging, the smell of smoke is fading, and there is a feeling of normality and well-being.  The normal balance of nature is being restored.  It is almost a religious experience.

Technically, we are experiencing an onshore or marine push, also known as the Northwest's natural air conditioning, and it it being forced by an approaching upper-level trough (see upper level map)

Temperatures at 9 PM at Sea Tac was 65F was 79F last impressive 14F decline.  And we are just getting started.   Visibility has improved at all regional airports.

What you really want to know about is air quality.  The HRRRsmoke model forecast for 9 PM shows the coast pretty clear, but with residual smoke inland, particularly over central Puget Sound.  That is consistent with the red moon I see outside.

But the story at 9 AM Thursday is amazingly better, with the lowland pretty much cleaned up, with the sole exception being around the Maple fire over the SE Olympic mountains and its plume extending to the NW.  Those living in western WA will feel energized and reborn.

But as in life, there are winners and losers.

Western Washington wins.  Eastern Washington loses.  Smoke from fires over the eastern slopes of the Cascades will flood eastern WA and Idaho, and increasing winds associated with the changes will increase fire threats on the eastern Cascade slopes.  Enjoy the change.
7AM Update:  Here is the particulate levels (PM2.5) ending 7 AM in Seattle.  Huge drop.

The 9:10 AM visible satellite image shows low clouds engulfing western Washington, but eastern Washington covered in smoke. Want sun and not much smoke?   Head to the upper western slopes and crest of the Cascades!


  1. How long is the onshore flow expected to last? Are we in for another round of smoke once high pressure returns?

  2. Do you foresee Western Washington getting these winds back our way anytime soon?

  3. Don't think the wind patterns would change like that but that would be something. Stoke up the fires in Eastern Washington then blow it all back over to the West.

  4. How does a layperson reconcile the data shown in that graph from the 7AM update with "Seattle-10th & Weller: 8/23/2018 5:00 AM WAQA Value: Unhealthy (157)" that is shown here: ? I find the conflicting information out there confusing.

    1. Agreed Becky, the current AQI in Shoreline is 188. Just as bad as yesterday.

  5. It's actually raining in Issaquah. Thank God! Don't think my lungs could have taken another day of that smoke. Clean air button on the air conditioners were ineffective.

  6. No significant relief in north Whatcom County. Breezy and cool (too cool for me!), but still smokey and low visibility.

  7. @Becky - according to WAQA values are more stringent than AQA - they have lower thresholds for unhealthy concentrations of particles so their values are higher.

  8. Some welcome drizzle in Auburn....yeahhhhh

  9. I was watching the website this morning since it has more neighborhood-by-neighborhood information. At 6:30a, West Seattle was still around had PM 2.5 counts around 40-60. Then by 7a the Tacoma sites showed drops into the single digits and by 8a that sweet, clean air hit West Seattle. It was fun watching it progress north through Seattle and push out the bad air on the eastside and then push north there as well.

    I will probably add an air quality sensor by next summer to my PWS. My only concern with them is watching how many had major A/B channel differences as the air got worse. I wonder if they start to fail under the extreme conditions or if they'll get back to normal over time.

  10. Port Angeles is still in the red zone. Everything around us is improved on the EPA map.

  11. When will eastern washington see some relief? I am planning a hike over there at colchuck, but now reconsidering.

  12. Hello from Victoria BC. You might find this interesting.

    Late yesterday evening there was a huge spike in fine particulates followed by a rapid improvement in air quality. During the spike, the air was so bad that the fire department was receiving calls from folks wondering if there was a local fire. I suspect the advancing marine air was pushing and concentrating the smoke that had collected west of Victoria; kind of like a snow plow clearing the road. Everything behind the leading edge was cool and clean.

    This dramatic change can be seen in the sensor data here (select 'PM2.5 (1 hr avg) in µg/m3'):

  13. Started getting better near Sequim this AM and then it came around the Olympics from the SE with smoke and particulate counts way up from 43 to 153 in a short period. Still happening regardless of the early optimism.

  14. Cliff, we live in Port Townsend and this AM we drove down the Quimper Peninsula to Kitsap Peninsula and Kingston, and rode the ferry to Edmonds. Then we returned a few hours later.

    Upon leaving PT in the AM, the air looked pretty bad. Once we crossed the Hood Canal Bridge, everything was beautiful, back to normal --great views -- and for the first time all week we rolled down thewindows. Ahhh fresh air!

    But on the trip home, as soon as we got back on the Olympic Peninsula, air quality nose-dived. Especially around Chimacum and Port Townsend. The AQI numbers as of 2 pm tell the tale, Port Angeles looks terrible!

    Can you tell us why there are still some pockets of stagnating air while other areas have cleared out completely?

  15. Don’t worry the smoke will be back, it always is

  16. It looks to me like there are fires burning in western Vancouver Island with smoke flowing right into the Strait.

  17. Looks like they're already predicting this weekend we could get northwesterly pulling down BC smoke again and lingering into Monday and Tuesday??

  18. I am wondering why the smoke has such a horrible odor. It is nothing like a burning campfire. Any thoughts, Cliff?

  19. It appears the "smoke models" were incorrect as it has returned. There was some temporary relief during the day in Bellevue then the smoke returned AGI @ 125 according to the sensor. NOAA forecast incorrect ".SHORT TERM...Still some haze out there but air today certainly passes the smell test" ... nope, smells like a camp ground outside.

    These events really highlight the inadequacy of our systems especially in terms of access to real-time information: Apart from a few blogs access to information and guidance is lacking. Since air monitoring equipment is specialized and extremely expensive there are only a handful of monitoring nodes in a city. This may be acceptable if air quality did not vary considerably due to a number of factors. Bottom line - it's impossible to monitor ones exposure.

    Also, unless one owns a property and has the financial resources' to invest in central air conditioning and/or filtration systems for a small period of the year then occupants are forced to breathe poor quality air during these events. Dozens of new apartment buildings are being constructed to accommodate the working middle class who cannot afford homes in this area thanks to Amazon, Microsoft et al. These buildings are poorly designed, cheaply constructed in a few months and do not have any systems for extracting air since the units have at most a single window there is no effective way to create air flow. You're right Cliff, this isn't a new normal because things will get worse and its always the poorest among us who will suffer most. The state should pass legislation to force builders to install at least basic air filtration systems for those of us who are relegated to apartments, especially if they plan on continued forest mismanagement.

  20. While "new normal" for fires and smoke may not be literally correct compared to fires experienced 100 years ago, it is a new normal for what a high percentage of the population has seen in its lifetime. Perhaps more importantly, the causes of the recent fires are very different than the causes of fires 100 or 1,000 years ago. And I do not detect any suggestion that human activity (whether through human caused global warming or otherwise) is not a major contributor to the problem. What humans are doing to the only place the species have to live in ought to be a cause for alarm to everyone. Fires are only one of many adverse effects we are seeing from our activity. And now we have a federal government that is doing everything it can to roll back measures designed to curb these effects.

    There always seems to be this underlying tone in Cliff's message, like it's been just as bad a 100 years ago or Fort Vancouver almost burned down. And rationalizers and climate change deniers seem to latch onto these remarks. It's one thing to try to put things in perspective, but I think to at least imply that this is all part of a historically normal pattern misses the mark, particularly when it does not acknowledge that human-caused global warming is likely to be a contributing factor to the problem.

  21. Thanks for this blog, Cliff! Can you tell me why the air quality at Lake Forest Park consistently seems to be significantly higher than in other locations? Low-lying land? Winds from the S & SW pushing the smoke up against the hills? Thanks!


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