Valley Smoke Plumes

Information about my Atmospheric Sciences 101 class below
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The visible satellite imagery this morning was fascinating, with smoke in mountain valleys jetting out into the lowlands.

There are two fires on the eastern side of the North Cascades (Sugarloaf and Labor Mountain fires...see map below)

 

With sea-level pressure higher on the eastern side of the Cascades than over western Washington, the smoke is being pushed westward through the Cascade Passes and then jetting out into western Washington.

You can see this in the visible satellite image this morning around 9 AM, with smoke pouring westward in Stevens Pass and pushing out into Snohomish County north of Seattle.

The Seattle PanoCam this morning, looking north around sunrise, dramatically showed off the smoke plume.  Kind of beautiful.

This plume created a localized region of poor air quality that pushed into western Washington, north and east of Seattle.  Another smoke plume moved westward through the near-sea-level Columbia Gorge (red and purple are the worst air quality).

Look at the air quality at Gold Bar, west of Stevens Pass. You can see the sudden increase in smoky air this morning after midnight.  Not a good time to go on a hike in the pass! 

Even more impressive, the vertical laser profiler at Marysville showed the dense smoke moving aloft last evening, being densest between 500 and 1800 meters (1600-6000 ft).  Yuk.

Turning to the Olympic Peninsula, some smoke from the Bear Gulch Fire moved southward before taking a hard turn to the west (see visible satellite image below)

Some of the smoke was evident far offshore around noon today:

The good news is that by Thursday, the winds will reverse (be out of the west) and the smoke will be pushed back into eastern Washington.

Furthermore, by next Monday, rain and stormy conditions will move in...and that should essentially end the wildfire season.  

As a teaser, below is the predicted precipitation total for the next ten days.

There will be no Western Washington fires after this.  

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Starting tomorrow, I will be teaching Atmospheric Sciences 101, which you can take either in person or online.  

The description of the class is here: 

https://atmos.uw.edu/~cliff/ATMS101Y2025.html

For those over 60, you can take the class as an Access Student at a very low cost.  Here is information about the ACCESS program:

https://registrar.washington.edu/register/access/

 

How Unusual Was This Summer?

 Today is the last day of summer, so it is a good time to evaluate what has happened over the past three months.

Let's start with the average daily temperature.  Below is the deviation of daily temperatures from normal for the western US.

Cooler than normal over much of California and southern Nevada, but warmer than normal over Washington and western Oregon--by around 2-4°F.

For precipitation, much of California and eastern Oregon were wetter than normal, while most of Washington was drier than normal by a few inches.

Let's take a closer look at how unusual this summer was by looking at a few local observing locations.

Starting with the June 21- September 20 observations at Olympia, WA., from the late 1940s to this summer,  we note a slot increase by around 3°F over the period, with this year being warmer than normal but not record-breaking.

Interestingly, the high temperatures this summer were very typical, with only a slight long-term trend in heatwave temperatures.

This is something the media has not been noting....the warmest temperatures are not rising much.  The big warm-up is in the lowest temperatures each day.

 

For precipitation (below), we see a slow drying trend in a region-- a region that does not get much rain over the summer.  This summer was drier than normal, but not nearly the driest.

Now let's turn to Wenatchee in the Columbia Basin of eastern Washington.  Clear warning trend, and this summer was the warmest on record.  

Precipitation at Wenatchee?   Modest drying over the years.

As shown above, general warmth and dryness this summer was not universal over the western US, and mainly over Washington State and western Oregon.

Why, you ask? 

 Because a persistent upper-level pattern developed, with higher pressure/heights over southwest Canada (red colors below) and lower heights/pressure over California.  High pressure is associated with sinking air, producing warmer and drier than normal conditions.

Why was this pattern so persistent?   I cannot tell you for sure.

Finally, how good was the seasonal forecast made by the National Weather Service before the summer started?  As shown below, not that great....got the warmth over the NW but missed the cooling over the southwest.

Temperatures will warm up during the next few days, but nothing serious over western WA--mid to upper 70s at most.  

Enjoy it while you can.  In one month, we will be entering the murk of Northwest winter.

Prelude to Autumn: A Serious Front will Arrive Tomorrow Night

A serious "autumn" front will reach the Northwest coast tomorrow night, bringing regional rain and a reduction of local wildfires.

A front that arrives one day before the official start of autumn on Monday morning.

The visible satellite image this afternoon shows the front offshore (indicated by the red arrow).

This front has our name on it

A 5 AM Sunday morning, rain from the front will be moving through western Washington.

And by 11 AM Sunday, the frontal rain will reach eastern Washington, with residual showers over the western slopes of the Cascades.

The forecast total through 5 PM Sunday is healthy for September, with up to an inch in the mountains.  This rain, combined with the 60s through most of next week, will reduce wildfire activity substantially.

Talking about temperatures....western Washington will cool into the upper 60s on Sunday (see forecast below), warm into the 70s for a few days, followed by a sustained decline, with highs remaining in the 60s.  There will be a feeling of autumn in the air.

Why did the Beach Gulch Fire Explode Yesterday?

 The Bear Gulch Fire in the southeast Olympic Mountains really revved up yesterday morning and afternoon.

Four days ago, it was smoldering, with only minimal smoke (see below, arrow points to the fire).

Yesterday,  during the late morning and afternoon, it really started to increase:

And today, the plume of smoke was impressive, stretching hundreds of miles into Canada.

Just after sunset from Seattle last night, looking towards the Olympics, one could clearly see the smoke plume from the fire.

The fire increased dramatically yesterday, but why?

In fact, my last blog, made before the blow-up, gave the reason:  the sudden development of strong, dry easterly winds over the region.

I have spent a great deal of time studying western Washington and Oregon wildfires, and a major finding was that virtually all the big, westside blow-ups are associated with strong, dry easterly (from the east winds).

In fact, I just wrote a paper on the subject that was just published (here).

Yesterday morning, there was a surge of such easterly flow as transient high pressure built into eastern Washington, and a thermal low moved northward up the coast. High pressure to the east and lower pressure to the west drive easterly flow since air tends to go from high to low pressure near terrain.

You can see the development of the easterly flow in the lower atmosphere by looking at the weather observations from planes landing and taking off from SeaTac (see plot of winds and temperatures below).  Time is on the x-axis in UTC and increases to the left.  (16 /12) is yesterday at 5 AM. The Y-axis is height in pressure.  850 is about 5000 ft.  Wind barbs are shown (blue) as well as temperature (red lines, °C).  

The easterly winds really increased (to about 30 knots) yesterday morning.

Easterly winds descending the Cascades were warmed by compression and were very dry.

Warm air.  Dry air.  Strong winds.   All very favorable for fire.

Fortunately, the winds weakened yesterday and reversed, so the fire should decline substantially now.  No hot weather is predicted over the next week, and rain will come in late Saturday.

We are going to make the transition to fall weather, and there is probably no going back.

PS:  one more fun fact about yesterday.  Several stations away from the mountains experienced an unusually large diurnal range:  the difference between high and low temperatures in one day.  

 47 to 88 F at Olympia: 41F difference!  Several other locations were like that.  Why do you think that mountains work against such large daily temperature differences?  Leave your answers in the comments.

Flash Heatwave and Wildfire Threat over Western Washington

 Tomorrow is going to be fascinating. 

 There is going to be a sudden, intense heatwave over western Washington, with temperatures jumping into the mid to upper 80s at many lowland locations.

And then much cooler on Wednesday.

This west-side heat will be associated with powerful easterly (from the east) winds over the Cascade crest and western slopes, which will provide a fire threat.

Consider the temperatures forecast by the UW high-resolution ensemble (many forecasts) prediction system for Seattle.  Tomorrow afternoon, around 4 PM (red arrow), most of the forecasts are for the upper 80s!

Let me show you some forecast maps of surface temperatures.

Tomorrow morning at 5 AM, the region is relatively cool, with the warmest temperatures on the lower western slopes of the Cascades.

By 11 AM, things are really starting to warm on the western slopes of the Cascades, Olympics, and coastal mountains, with some locations in the 80s!

But 5 PM is another...and very warm... story.  Western Washington will be MUCH warmer than eastern Washington, with much of the west in the mid to upper 80s.  Cooler near the water.

Why so warm WEST of the Cascades?  

Because strong easterly (from the east winds) will be descending the western slopes of the Cascades and coastal mountains, and descending air warms intensely by compression.

Take a look at the surface winds at 11 AM tomorrow, with stronger winds shown by yellow and orange colors. The western slopes will be gusty!

Warmer air can hold more water vapor than cooler air, so relative humidity falls rapidly as the air descends.  At 5 PM tomorrow, relative humidity will be below 20% in large swaths of western Washington and Oregon.

Strong winds and dry air can dry out surface fuels and stoke windfires.  In western Washington and Oregon, virtually ALL the big fires are associated with strong winds from the east.

An important tool for wildfire prediction is a parameter called HOT-DRY-WINDY (HDW), which combines wind and dryness.  

The forecast of HDW for tomorrow at 11 AM, with red and orange colors being high values.  Major areas of concern are north of Portland,  southeast of Seattle, and over the northern Oregon coast.

The National Weather Service has a red-flag warning out, which indicates the potential for wildfire on the west side of the Cascades.

The saving grace for this situation is that heat and dangerous values of hot-dry-wind will not be in place for long, and we had some rain this week.  

Still, folks need to be careful.

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Get outside and enjoy the weather with Play Tennis Seattle. Find nearby hitting partners, coaches, classes, and join the Seattle tennis community. 

https://www.joinplaytennis.com/seattle

A Fall Front Approaches

September is a meteorological transitional month in the Northwest.   The jet stream starts to strengthen and move south, while we begin to feel the effects of the first autumn-like fronts of the season.

The climatology of precipitation in Seattle illustrated this.  The first shows the probability of getting a real wetting:  0.10 inch or more.  The driest period is roughly July 10 to August 10.  Things moisten a bit through the end of September, followed by the "great wetting" in October.

A modest Pacific front is now approaching and will reach our region tomorrow.

Below is a satellite image this (Saturday) morning.  There are some low clouds along the coast, but the front is offshore and moving eastward.  A weak disturbance is found behind the front, followed by post-frontal showers.

This satellite image reveals that the air behind the front is not very cold--which is typical for mid-September.  Cold air is associated with deep, cumulus activity, which is absent.

How do I know this? The infrared satellite image at the same time (below), which measures the temperature of the cloud (cold is white and high), indicates relatively warm/shallow clouds behind the front.

Now, let's look at the latest UW WRF model forecast for precipitation (color shading) and low-level winds with the front.  

This afternoon, the front is offshore.  There is a large wind shift with it!

The front makes landfall about 11 PM tonight. Rain on the coast.

Tomorrow morning around 9 AM, precipitation reaches the western lowlands and the western slopes of the Cascades.   Some showers form over eastern WA and Oregon.

As the Pacific air wraps around the Olympics, a Puget Sound Convergence Zone will form over the north Sound, with precipitation north of Seattle

The predicted precipitation total for his event is shown below. A moderate wetting over western Washington and Oregon, with light rain east of the Cascades.  

This event will substantially reduce wildfire activity around the region.

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Get outside and enjoy the weather with Play Tennis Seattle. Find nearby hitting partners, coaches, classes, and join the Seattle tennis community. 

https://www.joinplaytennis.com/seattle

Free Speech Rankings are Out: A Sad Day for All Huskies

It is a sad day for all of us who care for the University of Washington.

Also, a sad day for those who value the essential American principles of tolerance for varied viewpoints and freedom of expression.

Image courtesy of Daniee Pascoal

The latest College Free Speech Rankings were just released by the highly respected, non-partisan FIRE organization: disappointingly, the University of Washington was ranked VERY low in this critical area.

 How low?  

Evaluating hundreds of public universities, the UW was second to LAST PLACE.

 Considering all universities (public and private), the UW was in fourth  to last place (see below)

 

Public                         Public and Private

The UW received an overall grade of F for free speech.

But it is even worse than that.

37% of students admitted to self-censorship, 80% say that shouting down a speaker they disagree with is fine, and 42% say that it is OK to use violence to stop someone from speaking (see below)

Just stunning and frightful.

I have seen this intolerance on campus with my own eyes.

The nation is mourning for Charlie Kirk, a conservative activist who was gunned down while speaking at a university in Utah.    

Mr. Kirk, leader of Turning Point USA, was talking on campus during spring 2024, answering questions and debating with students in front of the UW Student Union Building, the HUB.  

I was there.  Most students were respectful, but some were aggressive and threatening.  One called him a Nazi, while some antifa types, clad in black, were banging their shields and umbrellas.   I was glad he had security...it was needed.

A few months before, I talked to a Jewish student who had been walking with an Israeli flag.  He was thrown to the ground, the flag ripped up, and burned.   

A faculty member I knew went through the Pro-Hamas encampment and was punched in the head.

For an extended period of time, the UW allowed an illegal encampment on campus, a group that regularly painted antisemitic messages across campus in the name of Global Antifada and the elimination of Israel.  Some messages called for the killing of Jews.

More recently, a new interdisciplinary engineering building was ransacked and defaced, with over a million dollars of damage.   Arrested individuals are yet to be charged.  

Viewpoint diversity and free speech are not valued or supported by many faculty.   For example, the left-leaning UW chapter of the Association of University Professors (AAUP) does not allow messages that contradict their highly politicized narrative.  The current moderator of the AAUP listserv regularly rejects messages from me and others for this reason.  This is why he rejected my last message:

 "we have been asked to prevent people from using our list to spread unsubstantiated rumors and misinformation."

University websites push a highly politicized narrative on DEI, land acknowledgements, and highly skewed "values."  Job announcements make it clear that only individuals with the right values need to apply.  An example from the UW School of Education:

A one-page diversity statement describing your identity, positionality, experience and commitment to diversity, equity, and inclusion and alignment to the APA's Equity, Diversity, and Inclusion Framework. In addition, describe your philosophy of teaching and learning, including how your work will further the College of Education’s commitment to racial equity and social justice.

No conservative who believes in equal treatment of all students would have a chance.

I could provide dozens of other examples, but you get the point.  

The University of Washington does not support the essence of an educational institution:  to be a place where free speech is welcome, where all viewpoints can be heard, and where no student or faculty member fears providing an unpopular viewpoint.