September 11, 2022

California Imports of Clouds and Smoke Aloft as Air Quality Rapidly Improves in Western Oregon and Washington

 Air quality is rapidly improving west of the Cascade crest as the easterly (from the east) airflow has been replaced with southerly (from the south) winds aloft.    And the change of wind direction and increased humidity should allow rapid control of the Bolt Creek fire near Route 2.  

This morning clouds and wildfire smoke is found aloft over our region...and you can thank California for much of that!

First, the air quality situation.

The latest AIRNOW map shows good air quality on the southwest Washington coast (green) and moderate levels (yellow and orange) around Puget Sound.  Poor air quality is found near the Canadian border, but that should blow north during the next few hours.  Air quality is only slightly high over the eastern slopes of the Washington Cascades....unfortunately, that may worse during the next day.


You can get a better idea of the trends of air quality (actually concentration of small particles--PM2.5) from a plot courtesy of the Puget Sound Clean Air Agency.  This shows particle concentrations at Seattle, Lake Forest Park (north of Seattle) and Bellevue.  A peak yesterday (particularly at Lake Forest Park downwind of the Bolt Creek fire), but a major decline this morning by roughly 75%.   


And there are some clouds aloft and even a few sprinkles this morning.  To appreciate that, take a look at the latest regional visible satellite image.  You can see the middle-level clouds (really white objects with shadows) and lots of low clouds over the Pacific.   Smoke (middle grays) is really obvious over eastern WA and OR, as well as the central Oregon Cascades.


The clouds, embedded in southerly flow, can be traced all the way back to Hurricane Kay off of southern California.   An infrared satellite image (below) shows this.    No need for a tropical vacation...the tropics are coming to you!


And a lot of the smoke over our region (mainly aloft) is also from California (see NOAA HRRR Smoke forecast for this morning), with a boost from the Cedar Creek fire in Oregon.  


Meteorologically, the key factors controlling our improving situation are the inland movement of the region of high pressure (the ridge) inland and the approach of low pressure offshore.   The weather map for roughly 5000 ft (850 hPa pressure) at 11 AM today (Sunday) shows the situation.   The result is increased airflow in the lower atmosphere from the south and southwest.

As a result, the latest HRRR smoke forecast is for the smoke to move out of western Oregon and Washington at low levels (8 PM tonight shown).   If your live in Puget Sound country or Portland you will breathe well tonight.   But our boon will bring declining air quality east of the Cascades.  Sorry.

There are a lot of lessons from this event.  We were able to forecast the potential danger (strong, dry easterly winds) with great skill.  Portland Gas and Electric strategically de-energized power lines, and at this point I have heard of no new fires down there.  

The west-side fires occurred in exactly the period they have always done (late summer) and under exactly the situation that is typical...strong easterly flow.    Clearly, the Bolt Creek fire was human-caused, which implies we need to get the message out more clearly about taking great care during such (short) threatening periods.  Certain media have been pushing a global warming connection, but I should note that this is not clear:  the latest regional climate simulations suggest that strong easterly flow during this time of the year will weaken under global warming.  Another important issue is the condition of the forests that burned....but that analysis will wait for another blog.





9 comments:

  1. I find it heartbreaking that every time we get the most severe fire weather conditions of the year I can no longer be hopeful and think maybe we'll luck out and get through it and not have major fires because the fact is there's so many crazy humans out there that play with fire every day that intentionally or unintentionally big fires are for sure gonna happen. I'm always an optimist, but can't really be that way with this because it never works out that way anymore.

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    1. Some people are no doubt careless, but others are pig ignorant. Many fires are still caused via exhaust manifolds of motorcycles in the offroad areas, to cite just one example.

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  2. The Bolt Creek (now Eagle Creek) fire appears to have originated in or very near industrial timberland not far above Beckler River campground, with much of that acreage fairly recently clearcut. Deforested areas and young plantations with residual logging slash such as these tend to incinerate fast. As it migrated west, the fire burned through a mosaic of primary forest at generally higher elevations, mature second growth with a relatively heavy deciduous component closer to Hwy 2, and industrial clearcuts directly above Baring. It will be interesting to see how each of these categories have fared comparatively in the aftermath.

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  3. Thanks for the updates Cliff as always. I wondered if you could speak more about the state of the forest and how this may have contributed to the fires rapid growth and intensity despite the weather conditions. I have experienced severe push back and personal harassment when suggesting this as a contributing factor within the hiking community. I'm not sure why the topic is so controversial since it's quite logical to me when I hike weekly in our forests and see for myself the lack of forest management resulting in the forest floor choked with thick brush, dead fall and trees growing too close together. We have experienced decades of fire suppression policy in this state with no signs of change. How can we move forward past the naysayers to drive meaningful action in this critical area?

    I am trying to understand what motives anyone would have for denying that poor forest management is contributes to wildfire intensity, growth, speed etc.

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    1. Certainly nobody deserves personal harassment for engaging in a discussion.
      I think part of the problem is that the "poor forest management" argument always seems to ignore the impact of logging and pushes the blame towards fire suppression. Slash-covered clearcuts burn really well. And without the trees, thick brush takes over quickly, adding additional fuel. And they're rarely replanted with any thought other than to maximize future timber profits, resulting in too many trees.
      I often see commercial logging presented as a solution instead of part of the problem, despite plenty of evidence of fires burning extremely well through timber land leases.
      Poor forest management is absolutely a problem. Better management needs to involve prescribed burns and selective clearing as well as stricter regulations and limitations on timber leases so our commercial forests are healthier.

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    2. This shouldn't be an either-or conversation. It seems pretty clear that better forest management would help us reduce or contain these wildfires better, but that doesn't mean that climate change isn't _also_ a factor in causing wildfires. Poor forest management is to wildfires what weather is to climate - it matters on a micro scale, so we need to deal with it - regardless of what happens on the macro scale.

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    3. Thanks all for the thoughtful comments, I agree with everything above. These issues are certainly very complex with Climate Change, Forest Management, Human & Political impacts etc. all combining into a "perfect storm" of sorts.

      It seems clear that in regards to Global Warming/Climate Change we're approaching the 'adaptation phase' and we need to implement solutions to minimize the impacts of a warming planet. I'd love to hear more from experts in Forestry and how we can advocate for better logging practices as Booger mentions current practices are making the problem worse.

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  4. We don't know yet the cause of the Bolt Cr. fire but you can't rule out completely the possibility that it was a sleeper fire caused by the same lightning storm that started other fires in the north Cascades recently. Regarding the comment by Booger about fires burning well in recently logged areas, I was on a fire in the Naches district some years ago where the fire was carried mainly through recently logged sections while adjacent unlogged areas did not readily burn.

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  5. I'm not a scientist, but an historic comparison of forest conditions would be pretty informative. In other words, forest mismanagement has made them 50x more fire prone, while recent warming has made them 0.2x more fire prone.... something like that. Sad that real information often doesn't make it into the headlines!

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