Why did the Beach Gulch Fire Explore 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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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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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.

Heavy Rain, Flooding, and Debris Flows at Mount Rainier Park

On Monday, I was contacted by Scott Beason, Park Geologist at Mount Rainier, who was looking for precipitation data.

Why?  

Because of a serious debris flow down "Dry Creek" on the southwest side of Rainier, that closed the Westside  Road on Saturday evening.  Look at the pictures of the aftermath (below).

Just to orient you,  in the image below, the area of interest is shown by the red circle and is just east of Mount Wow.

The debris flow, driven by very heavy rain, was even evident on local seismic data (see below).   Note that the slide action started around 0515 UTC Sept 7 (10:15 PM PDT Saturday, Sept 6).  

It turns out this event was caused by VERY heavy rain on Saturday evening associated with potent thunderstorms.

The regional radars showed substantial thunderstorm/heavy rain activity moving across the Rainier area (an image around 8 PM is shown below)

Looking closer at the weather radar at  9:15 and 10:30 PM below, you can see some heavy rain over the "dry creek" area.  Remember, weather radar can provide a measure of precipitation rate.

 

What were the rainfall totals in the debris flow areas?  There were no nearby observation stations;  the closest was at Paradise, where 0.85 inches fell around 10 PM.  1.4 inches fell between 8 and 9 PM at Crystal Mountain, a very impressive total.

We can add up the radar precipitation rates over time to secure the answer (see below).  By 10:28 PM, some locations in the area received as much as 2 inches, at least according to the radar.

So we know what produced the heavy rain that led to the debris flow:  potent thunderstorms.   

Did the forecast models predict them?  

To help answer this question, below is the rainfall total covering the period from the high-resolution UW forecast model for the 24-hour period ending 5 AM on Sunday.  The circle shows the area in question.

Moderate rain was predicted, but clearly the precipitation was underpredicted.  

Getting thunderstorm precipitation right is very, very hard, and accurate local forecasts of such localized heavy rain may never be as skillful as we would like.

______________________

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Details of the Extreme, Local Smokestorm

 I have gotten several messages about yesterday's localized smoke event, so let me answer them here.

First, the smoke concentration in some locations north of Seattle was the greatest in many years.   

For example, at Lake Forecast Park, values surged to over 300 micrograms per cubic meter for a short period at the surface (see plot below).

This is extraordinarily unhealthy air.  Fortunately, particulate levels subsequently declined rapidly in the evening as the plume of smoke moved northward.

If you want to get an idea of how unusual the smoke was at Lake Forest Park, below are the one-hour values for the past five years.  

Last night was the highest in the last five years.   It is also the greatest on record at that location (going back to 1996).   

Everything came together.  A significant nearby fire (Wildcat), the "right" wind direction (from the southeast), and the meteorology that would bring the smoke down to the surface.  

Several people asked: Why were the smoke levels lower to the southeast--closer to the fire?  This is illustrated by the particle concentration map below near the height of the episode.  Red and purple are high values.

Air quality was much better in the mountains than in the lowlands!

To see what happened, let's examine how the smoke evolved aloft, using the laser ceilometer run by Puget Sound Clean Air Agency on Beacon Hill of south Seattle (below).  Time is on the x-axis and height in meters on the Y-axis.  Keep in mind that 3000 meters is roughly 10,000 ft.  Red and yellow indicate either clouds or relatively dense smoke.

There were some low-level clouds between 6 and 9 AM (red color), which dissipated by around 10 AM.  But then smoke started coming in aloft around 11 AM (at about 800 meters above the surface).  

The smoke mixed down to the surface around 5-6 PM and started to lift later in the evening. This led to the rapid and profound air quality degradation.

This morning, air quality was significantly improved over western Washington, but poor air quality still persists east of the Cascades.

As I will discuss in my next blog, we have made the transition to a fall-like pattern and regional temperatures should be MUCH cooler during the next few weeks.  Wildfires should decline.

______________________

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Smokestorm Hits North Seattle

 Sitting in my office right now, it smells like wildfire smoke.

Looking at the latest (4:30 PM) PurpleAir air quality map, one sees a narrow region of very poor air quality (red and purple colors) over North Seattle and southeast Snohomish County.  Also Kirkland.

Why is this happening?   A plume of dense smoke from the Wildcat Fire east of Mt. Rainier (see map below)

Take a look at the visible satellite image around 4 PM (below).  You can see the plume of smoke drifting to the NW, reaching north Seattle and Snohomish County. 

Want to be impressed?  Here is the small particle concentrations at Lake Forecast Park, just north of Seattle, since June 1.    

 Wow.  The highest particulate values of the whole summer...nothing is close.

The air quality monitor inside my building has gone from green to a warning color:

The good news?  The models are suggesting a significant change in the wind direction, which should bring relief to western Washington.  And we will move to a cooler and wetter period, which will help suppress the fires.

___________________________

______________________

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