May 18, 2023

Wildfire Smoke Forecast

As an experiment, let's do a wildfire smoke forecast for Washington State, including the potential impacts at the surface.

The satellite image this morning at 6:31 AM was scary, with the southern smoke boundary just south of Olympia.  Low clouds were along the coast and some higher convective clouds were over Idaho. 

 Look closely and you can see the shadows of the Idaho clouds on the smoke plume.


The smoke appears most opaque in the early morning and evening when the sun angles are low.  Roughly 3 hours later than the above picture the smoke is more transparent; if you look carefully the southern boundary of the smoke is starting to shift northward.


It is critical to know the three-dimensionality of the smoke and Puget Sound Clean Air Agency ceilometer reveals the vertical structure (see plot below for the ceilometer at Marysville). (see below)

Nearly all the smoke is above 2000 meters...which is good.  Reduces the probability of mixing smoke to near sea level (e.g., to the large population of the Puget Sound region).


Here is the latest PurpleAir air quality map.  Terrible air quality to the west of the Rockies.  Some smoky air is mixing down in and near higher terrain over Washington and southwest BC, but the particulate levels are modest.


Smoke Prediction

Now the good news for Washington State. The winds are switching to more southerly and southwesterly, which should move the smoke away from us.

The predicted winds at 700 hPa (about 3000 meters or 10,000 ft) this morning at 11 AM are southerly (from the south) over western Oregon and Washington and southwesterly over southern BC (see below). 
Such winds will tend to move the smoke northward. And the winds at the same level tomorrow morning are even more favorable for pushing the elevated smoke away.


A profound cool-down is predicted starting Sunday, so get your sweaters ready.
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Interested in a free lecture at the UW on How We Will Stop Fossil Fuels From Causing Global Warming by Oxford University Professor Myles Allen?    It will take place at 7 PM May 25 at UW's Kane Hall and you can get more info and sign up below.  Professor Allen is a very good speaker and internationally well known;  the talk will probably fill quickly so make your reservation soon if you want to go.


15 comments:

  1. Hi Cliff, good news on the smoke! Would you be able to speak to the humidity levels east of the Cascade crest? This year im seeing my garage floor "sweating" as humidity in my garage is 70+% and the dew point is around 12 deg C so i presume that moisture could be condensing on my below grade garage basement. I dont recall it being this muggy for a while and there have been numerous thunderstorms. A storm on Tuesday knocked out power for 11k homes and there is currently a severe thunderstorm warning in effect for Cle Elum. What atmospheric properties are causing these conditions? Also, is there any publicly accessible data that shows tops of clouds?

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  2. Juan Browne of the Blancolirio aviation safety channel gives this May 17th update on the Sierra snowpack:

    High Sierra Snow Report! 17 May 2023 Nevada County, CA

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  3. So much for wanting until August for hot and smoky weather, I am very concerned about this summer as we should be, we already had 90s in the south sound and it's only the beginning unfortunately.

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    1. Tim....we are about to turn cooler and the smoke it out. Important to note that we often have a warm spell in mid-May and that Alberta fires are climatologically most frequent in May. The smoke was NOT from local fires. ..cliff

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    2. Sorry Cliff, the cult of gloom and doom doesn't accept logical and science based evidence.

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    3. Cliff, I did not know that Alberta has a fire maximum in early summer. Why would that be? I know the Southwest is like that because the southwest monsoon arrives in June or early July and provides rain in midsummer. But Alberta?? I would have assumed they have snow on the ground into April, with at least a couple months before the forest floor dries out.

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    4. The fires have burned about 478,000 hectares, or 1,800 square miles, across Alberta, British Columbia and Saskatchewan as of Monday — 10 times the average area burned for this time of year, according to the NASA Earth Observatory.- CNBC.com

      It doesn't matter what they data says. It matters what people experience. I've lived in Seattle 30 years and I don't remember seeing smoke in May. To say this is normal is ridiculous. The longer we put off giving a shit, the sooner we become extinct. Try explaining that to your kids.

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    5. jno62 I disagree. It DOES matter what the data says. People's "experience" is highly subjective and often wrong. There has been smoke in May before. And it were older (say 150 years) you would know that it used to be MUCH smokier around here.......cliff

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    6. We have had smokier summers in recent years, especially in this century, than in the 50 or so years prior to 2000. Smoke in May has been rare. I don't think you can blame people living here now for complaining about the smokier conditions. Nobody is alive to remember how things were 100 or 150 years ago, when there was likely smokier summers due to human caused forest clearing fires added to wild fire activity and zero fire suppression efforts.

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    7. wxman. No one is blaming anyone, but the truth is that the historical situation for thousands of years was that the region was far smokier during the summer. People are used to an unnatural fire suppression regime, which now is sometimes interrupted my big fires in an unhealthy, modified forest

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    8. Okay, Cliff, you may be right that my first 3-4 decades of living here I was experiencing clearer-than-natural summer days (the 70's through the 90's or early 2000's). So, excluding tropical islands, which obviously will have the cleanest air, what part of the USA will, in your best estimate, have the least smoky skies, including both human and natural sources, (not necessarily the fewest fires) in the coming decades?

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    9. Cliff, correct me if I am wrong, but the impression I get from your above response to jno62 and other responses you have made to similar statements about the increasing number of smokey summers, is that you believe it is due mainly to our past mismanagement of the forests and not to the increasing number of warm, dry seasons. I think both are factors operating currently but you can't prove that one is a greater cause than the other. There were lots of big fires and probably lots of smoke in the 1920s and early 1930s,before "mismanaged forests" became an issue and these were associated with a number of warm, dry summers in those years. There were fewer large fires and fewer smokey summers in the 1940s into the 1960s when fire suppression efforts were better but also when there was a series of cooler, damper summers. In the past 20 or 30s years there has been increasing fires, increasing smoke and more warmer, drier summers, of which "mismananged forests" has probably added to the intensity.
      As for your statement that this region was far smokier for thousands of prior years, I am not sure how you know this. It was probably smokier when white settlement began in the 1800s due to the addition of man caused burning of the forests and no fire suppression. But prior to this, the region probably went through extended periods of cool, damper weather when there were fewer fires and smoke, alternating with warm, dry periods when there was increasing fire activity. The forests and fuels likely built up during these cool, wetter periods which resulted in bigger fires during the warm, dry periods, but it was probably not always smokier during the thousands of years prior to white man settlement. i

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    10. Wxman....we know about past fires from paleo records (eg charcoal deposits) and tree rings. Furthermore, a lot of documentation by first-hand accounts during the 1800s, plus information handed down by native americans. Fire is a natural part of the environment and European settlers radically changed the frequency of fire and profoundly changed to forests...cliff

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    11. Jno62 says,"it doesn't matter what the data says. It matters what people experience.". Unless the data supports your experience eh? The climate change cult screams about "the science and the data, and calls those who disagree "deniers,". Those "deniers" perhaps have had a different "experience" than you.

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  4. When I was looking at Copernicus it appeared that the smoke we are receiving has an origin of Tibet/China, and was not the result of the mixing of air from Canada.

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

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