July 03, 2021

Wildfire Smoke Returns to the Northwest

 Announcement:  Special Blog on Tuesday

Was Global Warming The Cause of the Great Northwest Heatwave?   Science Says No

This extended blog will examine in detail the claims that the recent heatwave was driven by global warming.  Many media stories and the claims of some politicians are inconsistent with the best science.  I will give you the straight story.

Wildfire smoke is back over our region.   But for the time being, western Washington is being spared.

The visible satellite image this morning at 6:26 AM shows a lot of milky white smoke east of the Cascade crest, and low clouds along the coat.

The origin of the smoke is made clear from the prediction of the NOAA/NWS HRRR smoke model.  The image below shows the predicted integrated (or total) smoke in a vertical column at 7 AM this morning (red is the most smoke).  There are two sources of smoke:  the Lytton and other fires in southcentral British Columbia and several large fires in northern California.

As long as the winds are generally from the west, western Oregon and Washington will be spared the worst of this.  There are some modest grass/range fires in eastern Oregon (see below), but they are not producing much smoke and will probably decline fairly rapidly.  There are no significant fires in Washington State at this point.

The current AIRNOW air quality analysis at the surface indicates good air quality west of the Cascade crest (green), with moderate air quality (yellow) over eastern Washington and BC and poor air quality limited to the interior of BC (red).

With the absence of new fire starts, the situation should improve as smoke is blown to the east.  Below is the HRRR smoke forecast for noon on July 4th.  Looks good for Washington State.

We are in a situation very similar to two years ago, with fires in BC and California.  Oregon and Washington would see hazy skies at times, but the smoke stayed aloft.  Only nearby fires can bring a lot of smoke to the surface.

No rain is being forecast over the next week, with temperatures around 80F each day around western Washington.  Add ten degrees for the Willamette Valley.


  1. In your upcoming post it would be interesting to read your response to these recent comments by your colleague, Dale Durran, who was quoted in a Daily Beast article (which was republished on Yahoo) as follows:

    Dale Durran just endured a historic heatwave in Seattle, and perhaps more than most residents, he’s got good reason to be confident climate change had something to do with the regional madness that proved especially extreme next door, in Oregon, where dozens died.

    The professor of atmospheric sciences at the University of Washington told The Daily Beast that this past week’s monstrous stretch—which topped out at a blistering 108 degrees on Monday—was “so outside the range of previous hot spells in Seattle that it really stretches the credibility of anyone suggesting it is simply natural variability.”

  2. Speaking of smoke, when will fireworks be banned? The spike of PM2.5 last night was serious in N.Bend from 27- 161o before dropping. From 9pm through 1am fireworks were continuous including large aerial overhead rockets that are supposedly illegal due to high wildfire danger. I find it hideous that folks complain about wildfire smoke yet not only willingly pollute their own air, but also risk starting wildfires.

  3. I see that there's a remote chance that we'll see some precipitation in the west mountains on Wednesday (NWS forecast as-of today) - fingers crossed! Last light drizzle here near the foot of Mt Baker was June 30-July 1, and it was wonderfully refreshing (I have photos, and even a brief video - very tiny raindrops, but enough to wet the highway and forest).

    It would be interesting to know what Pacific conditions are - what's driven this odd year. Has the Nina-Nino pattern settled?

  4. When oh when will we get some much-needed rain?

  5. I noticed the number of the top 25 high pressures for the first 40 years (52-91) is 8 (2/decade) but for the last 30 years, there are 17 (5.7/decade). Casual observation, but...How could that analysis be improved? maybe some ogive curves showing percentage of days with pressure over certain levels ie. for the full range of daily pressure means for each decade. Shows pressure level as domain with the percentage of daily means over that level as the range.

  6. Thanks for this. Is it true that there's another potential massive heat wave coming in again in the next couple of weeks?


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

More Rain for the Northwest is Good News for Wildfires

After a very pleasant dry spell, another rainy period is ahead for the western side of the region and the Cascades on Friday and Saturday.  ...