The Smoke Situation is Rapidly Improving West of the Cascade Crest: But the Wind Threat to the East Remains

 As expected, air quality is rapidly improving west of the Cascades, with the transition complete by tomorrow morning.

You can see the changes in the west in the visible satellite imagery at 11 AM yesterday (top) and today (bottom)

The smoke plumes are now directed to the east, as the winds have reversed to westerly (from the west).

Low marine clouds have pushed up the coast and invaded coastal locations.    Air quality in the Portland area is hugely improved.

The air quality map at 11 AM (below) shows good conditions on the coast and NW Washington (green).   Moderate air quality over Puget Sound country, with some smoke trapped at low levels.  Such  low-level smoke will mix out today

There is s good air quality at high elevations in the Cascades, which are above the shallow smoke layer.

To illustrate the good conditions in the Cascades, below is the view at Paradise, on Mt. Rainier (about 5500 ft).   Nice blue sky!

The latest NOAA HRRR smoke forecasts predict a profound improvement in low-level smoke between today at 11 AM and tomorrow at 3 AM

And REALLY better by Saturday at 5 AM:

But there is a potential problem: much stronger winds on the eastern side of the Cascades: winds that could rev up some of the fires burning now (such as Little Giant).

The forecast winds for Friday evening could gust to over 39 knots over some areas of the eastern slopes of the Cascades.

And the predicted westerly winds in Ellensburg will increase substantially later tomorrow, according to the UW high-resolution modeling system:

Such winds will make fire management more difficult and promote fire motion to the east.

Need to watch this situation carefully.

Smoke in the West Means Relief in the East. The Big Threat Comes Later this Week

As predicted, the winds aloft have turned easterly (from the east), resulting in smoke from eastern Washington moving aloft over western Washington.

This is actually good news for eastern Washington, as it leads to reduced wildfire activity and eastward fire movement.

This situation is only temporary, and later this week the situation will reverse, again pushing strong westerly winds into eastern Washington... with the potential for renewed rapid fire growth.

The Seattle PanoCam shot at 7 AM was not subtle.  Lots of smoke.

And the visible satellite image clearly showed the smoke moving westward aloft:

Air quality is still relatively decent in most of western  Washington (green and yellow dots below), except for the western slopes of the Cascade Mountains

The fact that most of the smoke is aloft is shown by the laser ceilometers run by the Puget Sound Clean Air Agency (see the vertical plot over time at Seattle's Beacon Hill below).

Surface heating during the day shows mixing down some of he smoke later today, so surface air quality may decline.

The current pattern, with high pressure aloft over the eastern Pacific, is good for reducing winds in eastern Washington--which means less rapid fire growth (see max winds so far today below).

Less wind means less fire spread, which gives fire crews a chance to deal with the fires.

But there is a problem.    

As the upper-level ridge of high pressure moves inland (see forecast for Friday afternoon below), strong winds will push eastward down the eastern slopes of the Cascades

To illustrate, here is the surface wind gust prediction for Friday afternoon.  Not good.

Such winds will rev up the Little Giant Fire, which is the most serious fire of concern at this point

Finally, there is a lot of talk about this fire event having to do with climate change.  The Seattle Times and some current/past politicians have been particularly egregious about such claims.  

Such claims are demonstrably false, and I will examine this issue in detail in a future blog.

The fires were initiated by lightning and arson, neither of which is connected to climate change

Winds were critical, and they have no connection with climate change.

Fuel moistures were near normal before the fires, so all the drought and low snowpack claims are irrelevant.