September 04, 2017

Smoke and Heat Coming to Western Washington

For many Northwest residents, it is there version of weather hell, but unfortunately we are about to do it again... very warm temperatures (90s) and lots of smoke.    And it starts today.

Today (Monday) dawned with relatively clear skies over Seattle, with some high level smoke that had come from California and a hint of smoke on the eastern horizon.   The latter has our name on it.

A number of major and minor fires are burning now (see below), with the eastern slopes of the Oregon Cascades and southern Oregon being particular hot spots.  There are some major fires over the eastern slopes of the Cascades, most of them lightning initiated.

Yesterday's MODIS satellite imagery showed the smoky impacts of the fires, with eastern WA getting the blunt of the Cascade fires because the winds were westerly...that is going to change today.  Southwest Oregon is a smoke disaster.

Fire behavior varies during the day, with the more stable conditions at night often allowing the fires to "settle down".  But during the day, the surface heating can cause the lower atmosphere to become less stable and to mix in the vertical, which can allow fires to explode (or at least to intensify).     As fires intensify they can develop deep columns of smoke, often topped by pyrocumulus.   This happened yesterday to several of the WA fires.   

Yesterday, I was hiking to Burroughs Mt on the north side of Mt. Rainier (with Professor Dan Jaffe of the UW Bothell, one of our region's leading experts in atmospheric chemistry).  As we left Sunrise, there was only some stable smoke on the horizontal, but during the next few hours several of the plumes went vertical and developed into mushroom clouds of white and black smoke (see below).   

Some of the fire plumes were high enough and substantial enough to be picked up on regional weather radars (see below, the three blue-green areas are fires).   The ability to follow fires with weather radars is one reason Senator Maria Cantwell is working to secure some weather radars along the eastern slopes of the Cascades.

Now the problem.   For the last few days, western flow off the Pacific has kept air quality (and visibility) decent over western Washington.   But during the next 48 h, building high pressure east of the Cascades will allow an area of low pressure (the thermal trough) to build northward out of California and the development of easterly (from the east) flow over the Cascades.   Such easterly flow will move the eastern WA smoke over us and warm temperatures (particularly with flow descending the western slopes of the Cascades and thus warming by compression).    

Here are the surface pressure predictions (with lower atmospheric temperatures and surface winds).
Red and brown indicate the warmest temperatures (the devil's colors).

8 AM Sunday.
 5 PM Monday.   Warmer and the trough has moved in.  Look closely at the wind barbs and you will see they are easterly over the Cascades.

 5 PM Tuesday....even warmer and the trough over western WA stronger.  Cooling starting on the southern Oregon coast.

Around 90F today and mid-90s tomorrow would be a good forecast.   The big question is how much smoke will reduce the max temps.   

And how much smoke?  Here is the latest prediction of the Canadian Smoke Model (Firework), showing the surface smoke at 5 PM Sunday, Monday, and Tuesday.

Huge explosion of smoke over the Northwest during the next day with Beijing-like values over much of the area.  Yes, red colors are the worst.

The USDA Forecast Service also runs a smoke model and it also shows smoke moving into western WA (5 PM Monday and Tuesday are shown)

Well, you get the message...expect heat and smoke, wherever you are in the region.  

Want some good news?  Cooling and onshore flow will occur on Wed. and Thursday.  And temperatures should drop into a normal range for at least a week.   The sun is weakening quickly now, so there is a good chance the real heat is over for the year.  But no guarantees.


  1. I just moved my family here from Fairbanks Alaska. The heat is a welcome relief from the usually freezing weather starting around now. Being from interior Alaska we are used to the smoke but I'd prefer those sunny skies. I'm keeping my fingers crossed for 80's and 90's for a little longer. I understand everyone else though.

  2. It's weather like this that convinces even our local hippies to break down and get window air conditioners.

  3. I've lived here 3 decades. I don't recall anything like these 'smoke storms'. Why is this happening this year, not prior ones?

  4. Is there a website that has historical data regarding wildfire smoke? It seems like every summer gets worse. Living in eastern wa is borderline miserable dealing with all the smoke all the time.

  5. jeff, re historical air quality data: check out the epa website:

    The data won't distinguish between wildfire smoke and other sources.

    This is certainly the worst smoke year I remember and I've lived in the state since 1980.

    When we drove home to Winthrop last night it looked like a scene (Mordor) right out of the Lord of the Rings. A giant ominous dark cloud was hanging over the Pasayten wilderness and the upper part of the valley. Summer can't end soon enough for me.

  6. This is our fifth summer in a row of excessive heat and record temperatures. When does this go from natural variation to a climatological trend? Could we be at the beginning of human caused climate change instead of 2050 being the arbitrary start date?

    1. It does seem all too convenient that this is just natural variation. Humans are good at finding patterns, and this sure looks like one. We're setting records for 90s in September, LA is seeing their worst fire ever, Houston just saw Harvey, SF just set an all time record high (104!), etc etc. Cliff doesn't like to admit it, but there is a lot happening that sure looks like climate being influenced by hotter than normal conditions.

  7. M... don't forget what's happening in other areas of the world too... Australia just had it's warmest winter on record.

  8. You know what kills me? Seattle "progressives" think they're so smart, and will blame this on climate change, but they are too stupid and too lazy to look at history. Specifically, the 1902 Yacolt fire, which started in the same place as this one -- both by teenagers -- and whose effects in Seattle were the same.

    Oh, but that would be facts, and facts must NEVER be allowed to interfere with what a Seattle "progressive" thinks it "knows."

  9. I understand that you think this is stupidity, but respectfully, I am a reasonably intelligent human. I'm looking around and observing current events. These events look like a pattern- one that seem to point to a lot of activity that generally stem from increased temperatures, all happening at once.

    Looking at history is also exactly what I'm doing. That's the concept of "record" events. Harvey was the most significant rainfall event *in recorded history*. The gulf is currently hotter than it's ever been *in recorded history*.

    Slight derail, but I have a question for you:

    What if climate change is false, as we spend a lot of time switching to clean energy?

    On the contrary, what if it *is* real, and we've done nothing?

    What's your goal in denying that we should take action against polluting the planet?

  10. Not stupid at all. But make sure you have your facts right. For example, the Gulf was NOT warmest in recorded history. I am all for switching to clean energy. The more renewables the better!

  11. @m, your cult wants $100 trillion. You are a "progressive" living in a city that, for now, seems rich, and one that has elevated wasting money on symbolic causes to an art form. Fine, spend YOUR money on your latest flight of complete ignorance, but don't spend anyone else's.


Please make sure your comments are civil. Name calling and personal attacks are not appropriate.

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