Oregon Smoke over Washington. Ends Monday.

 The visible satellite image this morning shows a plume of smoke over Washington, smoke that mainly originated over eastern Oregon.

The effects of the smoke were pretty obvious over western Washington, with an attenuated, red sun rising to the east this morning:

The smoke is thick enough that the intensity of solar radiation has decreased noticeably (see measurements at Seattle below for the last three days below).   That means we will be cooler today as a result. 

Air quality is good on the coast, moderate over the western lowlands and the Columbia Basis, and poor over sections of eastern Oregon

The laser ceilometers run by the Puget Sound Clean Air Agency clearly show the smoke moving in aloft.  Here is an example from the instrument at  Beacon Hill, Seattle. The time is on the x-axis (increasing to the right) and the y-axis is height in meters (3000 meters is about 10,000 ft).  Quite a deep layer of smoke is moving through overhead.

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Nearly all the smoke is coming from extensive fires in grass, bushes, and scattered trees in eastern Oregon (see current fire areas below).  Numerous lightning and human-ignited fires have occurred in the rangeland of eastern Oregon, with other fires over the southern Oregon Cascades.   The extensive, lush flammable invasive grasses (like Cheatgrass) are a real problem.

For most of the summer, the smoke from the fires did not influence western Oregon or Washington because winds generally move from west to east in our region.

But during the last few days, easterly winds have prevailed, associated with a thermal trough extending into western Oregon.     To illustrate, here is the forecast weather map at 850 hPa (about 5000 ft) this morning.  The solid lines are like pressure and you can see the wind symbols.  Easterly winds over northern Oregon and southern Washington.

Below are  the air motions at the same level (5000 ft) ....something called streamlines.   You can see why the eastern Oregon smoke is approaching us.

Fortunately, the situation is going to change during the next 36-48 hours.

Here are the streamlines showing airflow at 5 PM Sunday.  The wind direction has radically changed...now out of the Northwest.  That will blow the smoke away.

To show the improved smoke situation, let me display the smoke forecast (total in a vertical column) from the highly skillful HRRR smoke prediction model.  

This morning at 8 AM. Lots of smoke.

Tomorrow morning at 7AM, still smoky.

But by 5 AM Monday morning, the switch to northwesterly flow was doing its magic, with western Washington nearly clear of smoke.   Tuesday will be even better.

Relief is on the way!

Superinversion on the Hottest Day for the Rest of the Year

 An inversion is when temperatures increase with height.  

Today a super-inversion exists, with extraordinary warmth aloft.

At 6 AM this morning, temperatures are in the lower 50s in the south Sound and upper 50s to around 60F in central Puget Sound (see map).  But looking to the western Cascade slopes, you see some warmer temperatures with some in the low 70s.

It was so chilly at local river valleys that fog and low clouds formed in some of them:

But now, let me shock you.  Right above Puget Sound, just a little over a thousand feet up, the temperatures are in the 80s!   

You heard that right.   In a few hours, that warm air will mix to the surface and high temperatures will climb into the the upper 80s to near 90F over the western lowlands.

The warmest day for the remainder of 2024 will occur today

Below is the temperature structure at 6 AM from aircraft data at SeaTac Airport.  Around 63F at the surface (452 ft ASL) and 80F at around 1600 ft.  AN INCREASE OF  17F in around 1000 ft. 

 Mama Mia...that is an inversion!

Can you imagine hiking up a local peak, such as Tiger Mountain, this morning?  You would hike from 55 to 80F within 30 minutes.

The sun will warm the surface today causing increasing vertical mixing.  Rapidly, the warm air aloft will be mixed down to the surface and lowland temperatures will surge.  

The UW high-resolution ensemble of many forecasts (below), suggests a high around 90F at SeaTac, with cooling over the next several days.

And there is one other thing. Smoke.

The wind pattern aloft will move some of the smoke from fires in central Oregon into western Washington.  In fact,  you can see the smoke on a visible satellite image earlier this morning:

As the atmosphere mixes vertically today, some of that smoky air will be mixed down, mainly over SW Washington.

Finally, let me give you some good news. The National Weather Service has a red flag warning out for the western slopes of the Cascades (see below).   

Fortunately, this is little chance of western slope wildfires today and particularly spreading wildfire.  Why?  Because strong easterly winds are not forecast today.  Major wildfire events require wind and western Washington wildfires require strong easterly winds.