Thursday, September 3, 2020

Wildfire Smoke Heading for Washington State

Scary, smoke-laden image at 6:56 AM Friday morning

_______________________________

Until this week, western Washington has pretty much escape wildfire smoke.   Few fires in British Columbia, less acreage burned than normal over Washington, and California smoke has remained to our south.
Today

August 3, 2017

But that is about to change.  And I have new tools to show you the smoke that are highly revealing.

Let me begin by showing you the smoke forecasts from NOAA's state-of-science smoke prediction system:  HRRR smoke.  These figures will show you the total smoke in the vertical--not necessarily at the surface.

5 PM today, some smoke is starting to move over NW Washington and a plume of denser smoke (purple color) extends southeastward from near Yakima.


The visible satellite image at that time (now) shows the smoke over the Strait of Juan de Fuca (orange arrow) and the eastern slopes of the Cascades (look closely, the smoke is subtle)


By tomorrow morning at 8 AM, a more serious slug of California smoke has reached Washington State (red colors), but as we will see, most of that will be aloft.


By 5 PM tomorrow, the smoke thickens further over us and lowers to the near the surface.  Not the kind of imports from California we prefer.  Moderate air quality at best.


NOAA has added some new graphics that show the 3D nature of the smoke, which really is very revealing.  The figures below show you a north-south vertical cross section through the atmosphere (the location of the cross section is in the upper right--from the northern C to Vancouver BC).  Seattle is around 700 on the x-axis.

5 PM today, there is some smoke aloft (18,000- 23,000 ft aloft) over northern Washington and lots of smoke over northern CA at low levels


By 8 AM tomorrow (Friday), the CA smoke has moved northward into Washington, but remains aloft.  Our air quality will remain ok, but expect the sky to look hazy.


By 5 PM Friday, the smoke has lowered, aided by lower atmosphere mixing forced by surface heating.  Sort of like the mixing that occurs when you turn on the heat below your hot cereal pot.  Air quality at the surface will decline over Puget Sound if this is true.


Finally, an east-west smoke cross section across Seattle at 8 PM Friday clearly shows low-level smoke over western Washington and dense smoke on the eastern side of the Cascades where there is an active fire.


As weather enthusiasts you are probably asking:  why this surge of smoke tomorrow? 

The answer is that there is an upper flow pattern with a trough of low-pressure offshore and a ridge of high pressure inland, a pattern that produces enhances southerly (from the south) flow, which pushes the CA smoke northward (see map for roughly 10,000 ft tomorrow at 5 AM).


The good news?  The air quality should improve over the weekend as the trough moves through and a normal pattern is reestablished.

_____________

My blog on the KNKX firing and cancel culture is found here.

_____

5 comments:

  1. That smoke off to the NW was very noticable on the Space Needle Panocam this evening.Until I read your blog post,I thought maybe that a fire had broken out on the Olympic Peninsula.

    ReplyDelete
  2. Technology is amazing. Thanks.

    ReplyDelete
  3. Is there any possibility that a written transcript of your weekly blog post can be made available? Internet connections are extremely limited/slow where we live on the Olympic peninsula, and listening to audio isn't feasible. Thanks.

    ReplyDelete
  4. Monday afternoon and the smoke has really rolled in - is this also the California smoke coming north? I checked DNR site and don't see any significant fires in Washington, so am thinking weather patterns over the last couple of days have pushed more smoke our way...

    ReplyDelete