November 16, 2018

The Air Quality Health Crisis from the California Wildfires

The smoke from the California wildfires near Paradise, CA is producing the greatest air quality health crisis in the modern history of California.   Schools, universities, and sports events are being cancelled.

Although the terrible loss of life directly caused by wildfires in and near Paradise should not be minimized in any way, the health impacts of smoke will be profound, with millions of people being exposed to high concentrations of wood smoke.  Hospitalizations will surely increase and some increase mortality of vulnerable populations should be expected.

MODIS satellite imagery on Thursday at noon.  Dense smoke filled the central valley of CA and moved directly over the Bay Area.

For me, it is also personal.  My son, a healthy young man of 28 living in San Francisco, is greatly feeling that smoke as is his similarly aged co-workers and friends.  If young, healthy individuals are being sickened, can you image the impacts of those that are vulnerable?

The current air quality conditions around the Bay area are pretty extreme (see below), with much of San Francisco and neighboring areas in the very unhealthy range (200-300).   Looking at data around the world, it appears that San Francisco now has worse air quality than any major metropolitan area in the world, worse than even Beijing and Mumbai.

But what really stands out is the longevity of this poor air quality event-- extending 7-9 days now for many central CA locations.    From my perusal of the air quality data of the Bay Area Air Quality Agency and other sources, this event is unprecedented in the 20 year period of data available.

The meteorological set up that has produced this air quality disaster started with strong offshore-directed "Diablo" winds driven by a large difference in pressure between the western interior (high pressure over Nevada) and the coast (lower pressure or trough)....see weather map below for the morning of November 8th. These strong winds initiated the fires and thus the smoke.

 This was followed by a the building of high pressure aloft over the region (see upper level map for November 13th below)

and the development of modest high pressure over the intermountain west and a weak offshore pressure difference that produced light offshore flow, which moved westward through the Bay Area.  So there is no way for clean, Pacific area to reach the Bay Area in this pattern, and smoke from the Camp fires is continuously draining into the Bay Area.

But it is worse than that.  With high pressure aloft, there is sinking air in the middle troposphere (the lowest layer of the atmosphere that extends from the surface to roughly 30,000 ft), and that sinking aloft contributes to the development of a low-level inversion (temps warming with height)...something demonstrated by the radiosonde (balloon-lofted weather station) at Oakland yesterday morning.   Inversions acts as barriers to vertical motion of air.  The smoke is being held to a layer near the surface.

In short, we have had the "perfect storm" for dense smoke over the Bay Area and unfortunately this pattern is not going to shift in a radical way until next Tuesday. 

But there ISsomething positive to report.  The NOAA HRRR smoke system shows bad conditions today, but substantial improvement on Saturday as a weak push of marine air comes into San Francisco and the coast.  My son will be pleased.

Forecast of near-surface smoke at 5 PM today.

Some improvement on the coast and part of San Francisco Saturday at 4 PM.   


  1. My daughter's softball team was supposed to travel to the bay area from Seattle this weekend, but the tournament was thankfully cancelled. I greatly feel for the residents of California who have had to deal with crisis on top of disaster.

  2. My sympathies, cliff.

    Where IS that great conveyor belt of warm, moist, and clean subtropical air known as the Pineapple express, which usually brings much-needed rain to the west coast about this time of year??

  3. My sympathy as well.

    And Ansel's question is one I have. Not much analysis on line that I can find. One site I found a few days ago is Stormsurf: Its a fairly detailed site by surfers monitoring the Pacific for favorable wave action. Don't know how good his analysis is but seeing a walk through of the NOAA data on the Madden Julian Oscillation, ENSO, etc. was interesting. They are hoping for El Nino to deliver rain to California.

    Meanwhile via OSU's Prism database (accessed via my CoCoRaHS rainfall reporting account) I find we are in the driest November since 1936 (data queries go back to 1895). Pretty depressing to this rain loving person.

  4. "I find we are in the driest November since 1936 (data queries go back to 1895). Pretty depressing to this rain loving person..."

    And just two weeks ago we were finishing up an October that in many places (see the Olympics, and North and Central Cascades) that were substantially above average in precip, filling our reservoirs by as much as 20 feet - to the degree we are still above the 30-year average in reservoir height and they just dumped some ("some" in this case meaning >billion gallons) of it.

    And to Ansel, who asked "Where IS that great conveyor belt of warm, moist, and clean subtropical air known as the Pineapple express, which usually brings much-needed rain to the west coast about this time of year??"

    Uh, it just visited. Seriously, it WAS the weather before this. Here is Cliff's post about it from November 1 - two weeks ago - entitled "Aloha Winds"

    He talks about the the "Cascade foothills being inundated". Ansel - you even commented on it!

  5. Sunsnow12, here in Oregon we did not benefit at all from the storms you mention. October was way below average rainfall.

  6. In southwestern BC we have had a wet November so far due to the atmospheric river patterns at he beginning of the month that had Vancouver in the bulls eye and the heavy rain event this past Tuesday and Wednesday. Looks wet later next week too. We also had a wet September. And with his being an El Nino year look for the rains to really hit California in Jan-March. Only problem is with all the vegetation lost to the fires, mudslides could become the next disaster there.

  7. Sunsnow12 - I'm with you. I don't know where you're located, but our Cascades perspective is the same. The fall has been wet and cold here in Whatcom County below Mt Baker (which is loading up with snow). The new rain year (2018-19) Oct 1 to date has been very like last year's wet start, already over 14" RnYTD and trending cold. Here at 1 pm it's only 34'F at an elevation under 1000 ft, and with an overnight low of 26.1 hoarfrost is beginning to grow. Maybe the banana belt's weather is uncharacteristic, but that's the fringe.

    Gnolan, I'm CoCoRaHS too. Whatever may be happening down below, our cup runneth over up here. And I respect PRISM, but we have 81(+) years of local records in this area. Six - more like seven - of the last ten years have been wetter than average overall, and I've personally been observing from the same location for 45 of those years.

    Not having a crystal ball, I have no idea how the year will play out of course. But so far, "feet wet."

  8. 200-300 is unhealthful? In Medford OR last summer, we had days upon days of 500+. We (and other OR locations) were off the top of the scale. But now that it affects SF, it is worthy of comment in the national media.

    Join the club. Late to the party.

  9. Down in San Francisco for a business meeting. The air quality is very similar to what Seattle experienced this past summer. A thick brown haze. Folks are wearing masks while walking to work. Going for a run along the Bay is not a good idea. If the air is better today, I certainly can't tell.

  10. For the curious, a pretty good near-live image of the Berkeley-Oakland-Marin area from the Lawrence Hall of Sciece is located at the site linked below. Videos of the previous day's collected images are in the lower half of the page:

  11. What really blew me away was the weathercast showing smoke patterns and there were active fires in southern B.C. , Northern Idaho, and Eastern Oregon. It's November for goodness sake!

  12. Ellen, cool to see another CoCoRaHS observer posting. We have been at this location for 35 years.

    Its clear from current and years prior reading this blog you all are in a different world up there. On occasion I have read sanguine reports of favorable hydrology outlooks on this blog while we have low snow pack and reservoirs. What a difference a few hundred miles makes!

    Oregon State does a great job at outreach and sponsors a lot of citizen science sorts of programs. They help sponsor CoCoRaHS here and last summer a small group of us were accommodated for two days at the Andrews Experimental Forest where we were shown a number of the environmental monitoring programs ongoing there (and I got to meet and spend time with Dr. Chris Daley, the PRISM creator). What I wish, though, is having someone from say the College of Earth, Ocean, and Atmospheric Sciences run a blog more appropriate to our region.

    Meanwhile fingers crossed for rain next week.

  13. CA will get drenching rains next week. Their fire season will be over with, and the air quality will return to normal.

  14. Sunsnow12,

    Yes, I know I did... but it seemed like it didn't really deliver like it sometimes does, at least not in Bothell. Bellingham might not agree, though. (It was also cooler that it usually would be in October.) And usually, during an El Nino, if I remember right, the jet stream splits and California gets above average rain. So far this weather year they have hardly got anything. I guess I'm expecting too much.

    But I'm concerned that if the climate in CA warms even a little, it will get a lot drier and that much more combustible.

  15. From all of the photos and video I've seen, Camp was primarily an underbrush and structure fire. Most of the full grown trees look healthy.
    According to CBS, 12,794 structures burned, and photos show many vehicles. There must be plenty of "chemical irritants" in the air that wouldn't be there from a fire restricted to forest areas.

    1. As of today, November 19th, we are in our second Okanagan County inversion related burn ban.( previous burn bans this year were related to dry conditions).

      From my house right now I can see low-level smoke down the Methow valley south of Twisp. Looks to be from the smoldering Crescent Fire because there is still smoke visible from the direction near Black Pine Lake.

      Mazama has been suffering poor air quality this fall due to Forest Service controlled Burns on Sandy Butte.

      The purple air sensors at Mazama read 181 at 9:30 am.

      Currently I'm clearing a lot for a 3rd house project in a Wildland-development interface.

      I've been getting a lot of grief from the HOA Board because I'm cutting way more trees than they want me to cut. The head of the architectural committee was concerned because I was cutting most of the brush.

      Most of the folks who own homes in that development are from the west side.

      These are their vacation homes with good, but getting more expensive insurance policies.

      While the development is taking steps to reduce some of the fuel load, I've constantly pointed out to them that a 2% fuel load reduction is a drop in the bucket and we have to do more.

      However they seem to want to come to the east side and enjoy the beauty of the forest butted right up to their houses.

      I told the HOA Board that the brush grows back and I'm not going to build a house, have a family move in, and then see it burn down.

      What does it take for humans to learn the lessons from past mistakes?

      Chris H.
      Heli-free North Cascades


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

How unusual is it for aircraft to exceed the speed of sound?

Announcement:  Doing an online zoom session with Patreon supporters at 10 AM tomorrow (Saturday) ______________________________________ The ...