September 28, 2020

Smoke is Coming Back to the Pacific Northwest

I am really sorry to be the messenger for ill news.

But smoke is coming back to the Northwest later tomorrow and will be with us for several days.

California smoke.

Our skies will become hazy, the sun will take on that infernal reddish glow, and visibility will decline.

The only good thing is that most of smoke will stay aloft, but limited amounts will get to the surface in "favored areas."

The latest visible satellite image (1PM Monday) shows the problem:  massive fires are still burning over central/northern California and producing enormous amounts of smoke are being produced. Right now the smoke is blowing due west into the Pacific.  That is about to change.

The forecast weather map for roughly 5000 ft above the surface (850 hPa pressure) at 5 PM Tuesday, shows the evolving atmospheric configuration, with low pressure offshore and high pressure centered over Idaho.  This pattern will produce southerly (from the south) winds in the lower to middle atmosphere.   Winds that will pull the smoke right over our region.

Now, let me show you a recent forecast by the NOAA HRRR smoke model. Gird yourself. I will start by showing you the total smoke aloft.  

5 PM today (Monday).  Smoke over California and the offshore waters.  Where it belongs!  (purple is the worst,  followed by red, orange, and yellow)

By 5 PM tomorrow (Tuesday) the smoke has pushed northward up the Oregon coast and will just be entering southwest Washington.  Just in time for the big presidential debate!

And by 11 PM tomorrow (Tuesday), the smoke will be over western Washington in force as well as over the Oregon coast.

And the smoke will continue to move eastward over Washington State overnight.  Wednesday morning will dawn with smoke in western Washington.

Fortunately, the majority of the smoke will be above the surface, but the latest HRRR forecast for 5 AM Wednesday shows some smoke reaching the surface, particularly at higher elevations.    More smoke will mix down during the day as the surface heats and surface-based convective mixing brings down some of the smoke.  Northern California will have hazardous air quality.  Really bad.

Just for fun, I traced back the air over Seattle at 5 AM Wednesday using the NOAA Hysplit model.  Where did it come from at various levels? (ending at 500, 1500, and 3000 meters above the city).  

The answer is found below.  At 3000 meters (about 10,000 ft), where do you think the air over Seattle came from? DIRECTLY OVER THE FIRES.  No wonder we have a smoky problem ahead.    At low levels, the air is from eastern Oregon, where the air quality is now pretty decent.

Anyway,  we will have several days of high-level smoke ahead.  So enjoy the blue skies today and tomorrow.    

Much of the smoke will move in over Seattle during and immediately after the Presidential debate.  Whether there is a deep metaphor in this coincidence is something that I will leave to others to explore. 

KNKX and Cancel Culture is found here.

My 101 Class

As I have mentioned before, I am teaching Atmospheric Sciences 101, an introduction to weather and climate, this fall.  Not surprisingly, it will have to be online (Zoom).    But perhaps this is a rare opportunity as well.

As you know from this blog, I am really into outreach to the community through my blog and podcast (and previously my radio segment on KNKX).   I would like to try doing outreach this quarter with the online 101.

If you are over 60, you can sign up for the wonderful UW Access program, where for only a few dollars (I believe 5), you can audit UW classes.   So I encourage all of those interested in taking the class to do so.  Access students can't register until the third day of class, but I can give them the zoom address.

The class meets M-TH at 9:30 AM starting this Wednesday (Sept. 30th).  The class outline is here.


  1. Perhaps, since it is a clear night on Monday, post that there's a chance of a geomagnetic (G1,G2) storm anomaly, link below Monday post.

  2. Rats! And just when dad and I draggged our AC units back to storage last weekend...

  3. What is a good place around Seattle to watch the aurora? I remember someone had once said Tiger Mountain but I'm certain to get lost in the night.

  4. Cliff,

    Sometimes I think the broadcast meteorologists just read your blogs before presenting the evening news...!

    Is this smoke going to keep us indoors, or just haze over our blue skies? Curious as to whether outdoor exercise is off the table.

    Thanks, as always, for everything you do.


  5. Cliff, ACCESS registration is asking for information I don't have....e.g., SLN, DEPT(8 characters), section, and entry code. I can't find a blog where you noted those details....

  6. Cliff, with the upcoming favorable Martian opposition, (best until 2035) do you have any pull to open the Jacobsen telescope on campus for a very limited and safe star party? That 6 inch refractor would be the instrument of choice for our red neighbor, especially to people like me who don't have telescopes of our own. :( Hope to hear from you.

  7. My application is in for your class, but won't be admitted until the 3rd day of the quarter. I'd appreciate being mailed the Zoom link for the first lecture on Wednesday .. I don't want to miss the first day!! Is this possible?? Thanks.

  8. How far east do you recommend traveling to enjoy the blue skies. We're going camping and would love some area recommendations!

  9. Cliff,

    We have a 12 hour hike up to 7k feet near Darrington planned for Friday. Do you anticipate the smoke being both too unhealthy and the air too hazy for the time/effort?


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

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