Strong winds cause several major wildfires to rapidly develop in eastern Washington

Posted by

A serious situation has unfolded across eastern Washington today as strong winds associated with a cold front have resulted in a large dust storm along with the rapid development of several major wildfires. This rapidly evolving situation will continue to unfold overnight.

The explosive wildfire growth can be seen in shortwave IR satellite imagery. Black areas are hot spots associated with wildfires.

The rapid growth of the fire south of Omak is particularly stunning. The image below shows the approximate area burned, all of which happened today. The north-south length is around 20 miles. The most recent frames in the satellite loop suggest the wind has turned easterly, with the fire now threatening the agricultural areas and towns to the east.

Burned area for the fire near Omak as of 5 PM PDT Monday evening, via Inciweb.

A large plume of smoke is now covering much of central Washington. As the wind shifts to easterly, the leading edge of the smoke is rapidly approaching the Seattle area.

According to the HRRR-smoke model, near-surface smoke will rapidly overtake the Seattle area by 8 PM TONIGHT!

Even as I write this post the situation continues to rapidly evolve, with a new wildfire near Tri-Cities appearing out of nowhere in the last hour.

To add to the misery, the winds also created a ground-level dust storm in the afternoon hours. Washington Weather Chasers shared some dramatic footage of the dust near near Ritzville.

Maximum wind gusts (via AgWeatherNet) ranged from 30 – 60 mph.

Maximum wind gusts via WSU AgWeatherNet on Sunday 9/7/2020.

The smoke/dust has severely degraded air quality in central Washington, especially around Yakima. The ‘861’ reading in Yakima is likely an error, but the other readings of 150-200 (unhealthy) are certainly correct.

Air quality as of 5 PM PDT Sunday via https://aqicn.org/map/world/

How will this situation evolve?

The worst of this event may be yet to come. The east-west pressure gradient across the Cascades will continue to increase in the evening – overnight hours. Strong gap winds are expected through the mountain passes, Columbia Gorge, and Oregon Coastal Range. Combined with downslope drying, this is a very dangerous situation for rapid wildfire development west of the Cascades.

Looking at a slightly wider view, the HRRR wind gust forecast for 8 PM Sunday night shows that the strongest winds will be west of the Cascade crest, especially in the Portland OR area.

The gap wind event will continue into tomorrow morning (9 AM Tuesday morning pictured below).

Fortunately, winds will slacken in eastern Washington, which should slow the growth of the fires that started today.

Given the combination of strong winds and dry conditions, the fire weather risk is extremely high–levels that are rarely seen west of the Cascades.

There is a very real threat of rapid wildfire growth west of the Cascades over the next 24 hours. While large fires are rare in these areas, they are far from unprecedented. Any activities that could potentially start a fire should be avoided.

3 comments

  1. Are we getting some aerosol cooling in Seattle from the wildfires? How far under the forecasted temperature are we, if at all, and do the weather models take smoke into consideration?

    Like

      1. I think the smoke layer might be shallow enough right now to limit aerosol cooling. Not the case in Oregon though where the sun is completely blocked out!

        Like

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s