One Day Cool-Down and Strong, Threatening Winds in Eastern Washington

 Today, an upper-level trough of low pressure is moving through the region, bringing cooler conditions over the region and strong winds in eastern Washington.   

In fact, much stronger winds from an unusual direction.

Consider the forecast upper-level weather map (500 hPa pressure, around 18,000 ft) this morning (below).  A low-pressure area.... a trough...   is moving southeastward over the region, with high pressure....a ridge... over the Pacific.

This feature is pushing cooler, Pacific air into western Washington and Oregon, resulting in stronger westerly winds over the eastern slopes of the Cascades.  

But in the wake of the trough later today, strong northerly winds (from the north) will push down the Okanogan Valley into northeast Washington.

Consider the wind gust forecasts from the UW high-resolution weather prediction model.  At 8 PM Monday (today), it is going for moderate wind gusts...up to about 35 kt around Ellensburg and vicinity.  Typical summer conditions and why there are a lot of wind turbines there.

Today at the same time,  the wind gusts are even stronger around Omak and the Okanagan area.   Look closely, and you see the powerful winds are from the north....which is relatively unusual this time of the year.

A plot of the maximum wind gusts forecast through tonight shows a substantial strong wind area on the eastern slopes of the Cascades.

As of 3 PM (Monday), the strong winds were materializing, with northerly wind gusts to 68 mph in the Okanogan!  Wow.

With dry fuels in place, there is a substantial wildfire threat with these wind conditions, so folks need to be careful not to cause ignitions.

My colleagues at the National Weather Service (Spokane office) have strong warnings out (see below).  They also spotlight the particular danger in the Okanagan.  Another example of why we need the forecasts of the National Weather Service.

 

Midsummer Air Quality Check

 It is almost mid-July, and it is time to check on Northwest air quality.

According to the EPA's AirNow website, all measurement sites are showing good air quality (green dots), as shown below

The high-resolution visible satellite image today shows clear skies as well.

The biggest trouble spot for poor air quality is in Minnesota and neighboring states, with smoke from Canada.

The number of fires is now increasing as the fuels dry out and humans are causing ignitions.   We have been lucky with the relative lack of lightning this year, which results in fewer fires in remote areas.  

The good news is that little lightning is predicted over the next week...and we expect a gradual cool-down.