June 23, 2019

Preparing for Wildfire Smoke

There is no smoke over the Northwest right now and the weather should be cool/wet later this week, so there is no imminent threat of smoke over the region.

But some fires in the region are inevitable, and thus some smoke should be expected, particularly east of the Cascade crest.  This blog will examine expectations for the coming wildfire season and talk about common sense preparation that can make one "smoke resilient" for a minimal investment.

The Current Situation

There are no major fires in the Northwest right now and air quality is good throughout the region.    In fact, there are fewer fires than normal burning at this time.  The Forest Service Observed Fire Danger map (below) suggests low potential for fire right now.

And as illustrated by the accumulated precipitation forecast through next Sunday morning (below), the next week should be on the wet side (and cool) across the Northwest, with particularly heavy rain over British Columbia and Alberta. 

This precipitation will delay fires in British Columbia (which was a big problem last year) and over eastern Oregon and SW Oregon.  Although the models are suggesting a return to more normal, warmer, drier conditions in early July, this wet period will sufficiently moisten the surface to push wildfire season into mid-July or beyond.

At this point, there is no reason to expect more wildfires than normal or a particularly smoky season in western WA.  I suspect that a repeat of last year's, two-day "smokestorm" is unlikely.   But some smoke over the region is nearly inevitable.

Reflections of last year's smoke

Smoke is unpleasant, but one needs to keep the "threat" in perspective.  Take last summer.   Although there was several weeks of smoky haze, most of the time the smoke stayed aloft above western Washington, with relatively clean air at the surface. 

To illustrate,  here is the concentration of small particles (PM2.5) in Seattle over summer 2018.   Most of the period was fine (under 20), but there was a period from roughly August 11-August 25th that was quite bad.  Also note the spike on July 4th!  So we are talking about a few weeks... no more.
Spokane?   They had one HUGE spike for a single day, and an extended period of moderate smoke that encompassed much of August.  They are closer to many of the fires than Seattle and don't enjoy as much of the clean air off the Pacific.  But still, much of the summer was fine (e.g., June and most of July).

Taking steps to get ready for smoke

The time to get ready for wildfire smoke is now--critical local supplies will be gone once air quality starts to decline. 

High-quality air filters can make a huge difference.

Last summer, I do some experiments using a cheap box fan, with a high quality furnace filter mounted on its intake side.   Professor Dan Jaffe at UW Bothell, an air quality expert, did the same.    The impacts were huge---this simple setup took most of the wildfire smoke out of the air.  We also found that without filtration, inside air wasn't much better than outside air.

Puget Sound Clean Air Agency did similar experiments (see below).

The key is to get a very good furnace filter (MERV 13 or FPR 10).     Yes, they cost more (about $20), but are worth it.

So if you have a house or apartment with a forced air system, get one of these good filters, and when there is smoke around, keep the system running 24 hours a day (most thermostats have fan settings).   And, close the windows if you can.  You will breath much better.

If you can't follow that approach, purchase a cheap box fan (they are about $20) and a 20" by 20" high-quality furnace filter, mounting the latter to the fan. (Puget Sound Clean Air agency provides instructions to do so) and there are several YouTube videos on the topic.

If you want to spend more money, you can buy commercial air purifies for $50-150.

Another possibility is stock up in a high quality filter mask, but be sure to get one that is at least N95 or N100.  But wearing such masks gets old, real fast.

Whatever approach you take, it is best to stock up now.  Last year, the stores were stripped of filters, fans, and masks as soon as the smoke started.  At my local food store, there is a huge pile of box fans available for purchase.

Better Smoke Prediction

There is one element of the smoke business that is radically changed compared to even five years ago:  highly skillful smoke models run by NOAA, Environment Canada, and others.  My favorite has been the NOAA/NWS HRRR smoke model (see below), which can give you warning a day in advance of smoky trouble. You can also use the output of such models to plan day trips to less smoky locations.

In short, there is much you can do to lessen exposure to wildfire smoke. 

Wildfire smoke has historically been a fixture of the region, and the unnatural suppression of fires has led to forests that burn catastrophically.  Better forest management and the return of regular fires (some from prescribed fires) will lead to an improved situation in the long-term, but some summer smoke should be expected each year.


  1. Good post.

    Sad we have the pearl clutchers in the media and on the /r/Seattle reddit fanning the flames like we are going to have "Smokepocalypse Now" this summer.

  2. The forests of Canada have become increasingly over-mature and fire-prone, especially in Alberta. Those forests naturally burn about every 200 to 250 years. They really need to be logged and replanted, but the "environmentalists" will never agree. They'd rather see them burn, so they can blame it on "climate change" as a way of pushing their cult agenda.

  3. It is so unfortunate to read the previous two posts. "Environmentalist and their cult agenda." "Pearl clutters." Please understand that climate change is not an agenda. This is the product of decades of hard science. I know this because I am a scientist (Wetland Ecologist). I first heard about the concept of global climate change some 40 years ago as an undergraduate. I have also worked with the Forest Service in the Pacific Northwest as the Service studied how to conduct prescribed burns so that the impact to the air we breath is minimized. I have a very good understanding of the issues affecting the Pacific Northwest. Climate change is a real thing that the Earth is experiencing right now. This is coming from scientists, not "environmentalists."

    As for the forests, the problem is the result of a century of active fire suppression. It is not logical or rational to blame the Canadians for the state of their forests. Ours are as bad or worse. The Canadians have been practicing thinking and selective logging to a far greater extent than their American counterparts. None of this addresses the severe buildup of fuels within the forests. After a century of suppression, our forests are ripe for major conflagrations. We have seen this already in the past couple of years. It would seem that fires are becoming more severe and more destructive. This is because they have become more destructive. The low-level under burns that were common before the arrival of the Europeans cannot happen now.

    It is not rational to blame the current state of our forest or the current state of the global climate on "environmentalists," "leftists," "Conservatives," "Chinese," or whoever. The problem is now upon us. The time for finger-pointing is long past.

    If you are not part of the solution, you are likely part of the problem.

  4. I would like to hear a response from Cliff to the above post. David Teasdale has a B.A. in biology from Grinnell college and a master's in ecology from Illinois State University. Wetland delineation in Washington state requires very little training and is not based on physical science properties, even though that is what is discussed in the Army Corp manual. It is very sad how science degrees have become so diluted in terms of rigorous physical science. That's one of the problems in climate work and computer modeling of said work.

    1. As someone who also has a science degree (Env. Science/Hydrology) I can assure you that we had many physical science classes, including computer modelling and atmospheric sciences. What’s your degree in? Why do you have to denigrate earth sciences. You make it sound like to do wetland delineation in Wash you only need to take some short online course.

      Get off your high horse.

    2. A B.S. degree in geology is a serious physical science degree. A B.A. in Biology is a nice degree but not a serious physical science degree unless specific electives are chosen. In Washington in many counties, wetlands are delineated by plant species found and the hydric nature of soils is not directly tested. My degrees are in chemistry, BS and MS.

  5. A major part of no planned burns is all the people who have built houses in the middle of the forest. What do you do about them and to them. If a planned burn gets even a little out of control legal liability cranks in. And don't even think about telling people they can't live in the middle of the forest. Cliff has discussed this.

  6. Placeholder, there is no way all the forests of Canada could or should be logged, and both countries have set aside large tracts for noninterference as much as possible, i.e., the Wilderness Act, etc. Believe, me, no sane person likes forest fires. They interfere with both health and recreation. I think we are seeing 2 things, as Cliff says: The overgrowth of small trees, as a result of suppression of all fires, and a warmer, longer summer season. As he says, I am afraid that some fires are a normal part of the western ecosystem. The early part of the 20th century was apparently very smokey, and the 70's and 80's were unusually smoke- free because of fire suppression. If you don't like fires, you can trade them for humidity and live in the east, where I grew up Those deciduous forests rarely burn because they get rain every few days all year. Everyplace has its good points and bad points.

    I do think the media are over-hyping it. There's no reason to expect a worse-than-average smoke season, even though we have had two in a row.

  7. Mr. Tessdale is found trafficking in the canard of "an appeal to authority," which gives the game away via his voluminous text proclaiming his alleged (and of course, superior) expertise. Rather than support his arguments, he falls back on credentialism.

  8. For "Caroline" - your statement here: "It is very sad how science degrees have become so diluted in terms of rigorous physical science. That's one of the problems in climate work and computer modeling of said work." has to be the most obviously thoughtless thing I've read in a long time. And I don't say that easily. Who specifically are you talking about? Which people?

    You start off warbling about wetland delineation and then take a hard right hook at climate modeling - which is weird as they aren't the same thing.

  9. Wow Caroline, do you really need "to hear a response from Cliff to the above post"? If this above post said something you find fault with (seemed pretty reasonable to me) why not call it out instead of attacking the credentials of the poster? Since you took the time to do some personal research for the sake of a thoughtless personal attack.

  10. Wow Caroline, do you really need "to hear a response from Cliff to the above post"? If this above post said something you find fault with (seemed pretty reasonable to me) why not call it out instead of attacking the credentials of the poster? Since you took the time to do some personal research for the sake of a thoughtless personal attack.

  11. I’ve argued on this blog that climate change has contributed to the worsening of forest fires. Mostly a pushback to “climate change had nothing to do with it”. The problem is with QUANTIFYING the impact. Could be 5% or more. Could be tiny, less than 1%.

    If the subject wasn’t so complicated, we might see concrete numbers like this:

    65%: increased fuel load due to years of fire suppression
    20%: poor replanting practices, ie, trees too close together
    10%: Increase in human caused ignitions
    3%: drier forests due to higher temps (climate change)
    2%: extra flammable invasive species

  12. Yep, looks like we're screwed as lightning is now forecasted in the mountains Wednesday and Thursday. I'm apprehensive with the thought that it might be smokey again this summer.

  13. I have one minor comment: box fans, and fans in general, are better at blowing (exhaust) than sucking (intake). Since circulating the room air through the filter is the goal, the filtering isn't affected by which side of the fan you mount it. Therefore, it performs better if you attach the filter to the exhaust side of the fan so it can push the air through it.

  14. Hey, the predicted quantitative rain forecast map, why the non-intuitive sequence of colors?


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

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