I-90 Dust and Dry Spring

Dry and windy conditions on Saturday led to blowing dust on I-90 between Moses Lake and Ritzville, which contributed to a seven car pile up accident at MP200.  East bound lanes were closed, along with 1 west bound lane for about an hour.  Here is a picture courtesy of WSDOT.

Blowing dust on Interstate 90 - Photo courtesy of WSDOT

 

The worst of the dust on I-90 was seen on satellite imagery from 2 to 4 pm.  We tweeted a satellite loop showing the dust tracking across I-90 from north to south east of Moses Lake.  To see the loop, please click here

NWS Spokane Twitter post at 4:04 PM April 11th, 2020

New GOES-17 Satellite imagery also picked up on the dust, as shown by the darker pink colors near Moses Lake.

GOES-17 Dust RGB 2 PM - 5 PM PDT April 11th, 2020

And a more zoomed in look

So, what were the winds doing during this time frame?  A WSDOT sensor from Warden is shown below.  Winds were sustained around 25 to 30 MPH with gusts up to 42 MPH.

Warden observations

Here is a broader view of peak wind gusts from April 11th

Peak wind gusts from April 11th

So what other factors led to the dust besides the dry and windy conditions?  For one, spring planting is ongoing with some freshly plowed fields.  Second, it has been very dry since the start of the water year across Central WA with many places only receiving about half of normal precipitation.  Even less for the Yakima Valley.

Moderate to locally severe drought is depicted in the latest US Drought Monitor

US Drought Monitor released April 9th, 2020

And while Central WA has been noticeably dry, it's worth noting that all of the region has been much drier than normal over the past 60 days.

What has caused this dry weather?  A large and persistent upper ridge in the Eastern Pacific.

The pattern this week looks similar, with a strong ridge off the coast providing more dry weather to most of the Inland NW. 

We will have to keep an eye out for more blowing dust potential across the Columbia Basin with any strong winds that develop given the dry soils and current Soil Moisture Ranking Percentiles.

Fortunately, at least for this week no strong winds are expected although breezy conditions are possible Tuesday night into Wednesday, but not as strong as what occurred on April 11th.  Also with the dry weather fire danger is above normal for the time being so pay extra attention to any burn restrictions for your area.