Alaska Wildfire Smoke Reaches the Pacific Northwest

The visible satellite imagery this morning clearly showed a plume of smoke aloft extending southward over eastern Washington:

This smoke originated from some large fires over Alaska and northern Canada, as shown by the AirNow graphic:

Most of this smoke remained aloft, but some surfaced east of the Cascade crest, resulting in moderate air quality (yellow dots).

Why did the smoke push down in the Northwest?  

Because a ridge of high pressure developed over the eastern Pacific and winds are northwesterly on the eastern side of such features (see upper level (500 hPa pressure, about 18,000 ft) map at 5 PM Sunday).

Fortunately, the pattern is already changing, with the air flow turning more westerly, pushing the smoke to the east.  Expect better air quality aloft this week, including a turn to cooler, wetter weather.

Finally, I should note that there is relatively little smoke contribution from local wildfires in Washington State.  Today, there are only three modest fires in or near Washington State (see map).

The slowly growing 1000-acre Pomas fire near Lake Chelan, the 2000-acre Barstow Road fire burning in grass and farmland, and the 3700-acre Rowena fire burning in grass and logging debris.  The Rowena fire is nearly completely contained. 

As I will describe in a future blog, it has been a below-normal wildfire year so far in Washington State.