Misinformation in the Seattle TImes Anount Drought, Snowpack, and Climate Change

It is frustrating to read stories by the ClimateLab folks in the Seattle Times that are simply not true.

Another story was published yesterday that predicts a major drought year ahead due to poor snowpack.

A poor snowpack driven by climate change.

The problem:   their claims are easily shown to be false

The Truth

In December,  the region was hit by several strong atmospheric rivers that produced massive precipitation.  

Soils became saturated, rivers flooded, and all regional reservoirs were filled to above normal levels.

Atmospheric rivers are associated with warm conditions, thus working against snowpack accumulation.  And January was relatively dry and warm aloft due to high pressure aloft.

Consider the critically important Yakima River reservoir system.  

The heavy rain caused a huge increase in reservoir storage (blue line).  Higher than ANY TIME OF LAST YEAR and equivalent to early May levels in a normal year.

Yakima water storage will easily reach 1 million acre-feet just with rain and melt last month, resulting in a full reservoir system.

To provide 100% of the water requested, the Yakima System needs to deliver 2.3 million acre feet, with the remainder coming from melting snowpack AND late spring/early summer rainfall.  

We are only halfway through the snow accumulation season in the Cascades, and there is PLENTY of opportunity to gain much more snowpack.

Currently, the snowpack in the Yakima Basin is roughtly 48% of normal, and this percentage will only increase...and substantially.   

Evem of there was no additional snow this year, just rain, one would expect about 750,000 acre-feet from melting the snow that is not on the ground.

So WITH NO SNOW, we would get to  1.75 million acres feet.   76% of normal.

Snowpack percentage of normal yesterday for the Yakima drainage.

But we are only about halfway through the snow accumulation season, and models are going for a cooler/snowier period ahead.  For example, the European Center model predicts lots of mountain snow through February 22:

Extended seasonal forecasts are for a wet spring with normal temperatures (see below).

That means plenty of snow.

Moving beyond the Yakima River situation, snowpack is above normal over the eastern slopes of the North Cascades, and the snowpack supporting the important Columbia Basin is normal (and the water level behind the Grand Coulee dam is above normal).  

Regional reservoirs are in very good shape.

No drought.

Even Worst

As bad as all the unsupportive Seattle Times claims of regional drought, there is clear misinformation about the cause of the lack of snow last month.

The Seattle Times claims it is because of warming due to climate change."

Substantial portions of the article push the global warming origin of the thin snowpack.

This is demonstrably untrue.

The last month was warm and dry because of the persistent ridge of high pressure over the region.  

The map below shows the anomaly (or difference) from normal of the heights (equivalent to pressure) at 500 hPa (about 18,000 ft).  

A very strong ridge of high pressure over the western U.S. and an intense trough (low pressure) over the eastern U.S.

This pattern suppressed snow over the Western U.S. and ENHANCED snow over the East.

Such patterns have little to do with global warming (there is a VERY published literature on this).

The claims of the Seattle Times that our low snowpack is connected with global warming are simply false, with the impact of global warming on regional snow quite modest, something proven by the lack of downward trend in the observed Northwest snowpack over the past decades. (see below, SWE is snow water equivalent, the amount of water in the snowpack).

The continued deceptive information from the Seattle Times on climate issues is very worrisome and shows the dangers of journalism funded by advocacy groups (the Seattle Times Climate Lab sponsors).

Super Inversion But Decent Air Quality

I will define a Super Inversion when temperature increases by more than 20F in the lower atmosphere (from the surface to roughly 3000 ft).

As noted many times in this blog, temperatures normally decrease with height, but in inversion situations that opposite occurs.

Inversions represent stable situations that suppress vertical mixing, and thus encourages low level fog and pollution.

The lower-atmosphere temperature structure near SeaTac Airport is shown below, based on observations taken by aircraft arriving or leaving the airport.

Around 43 F near the surface and 63F around 2200 ft.  Wow.

The effects of the inversion were obvious in the surface temperatures around our region (see below).   East of Seattle, an observation location on the slopes of Squak Mountain was 51 F, but 33 F was observed at lower elevations not more than a mile away.

Or consider the situation near Route 2.  57F near  Gold Bar but near freezing a few miles away to the west at lower elevations.

The strong inversion was evident in the observations from the balloon-based radiosonde at Quillautye on the WA coast (below).  The red line is temperature (in °C), and the height (y-axis) indicates pressure (700 in about 10,000 ft, 850 is about 5000 ft). 

At this location, temperature increases by 13 °C (23F) in the lower few thousand feet.   Wow again.

Mama Mia!  That is an inversion.

Such strong low-level inversions result in an atmosphere lens that bends the radar signal down to the surface.  

And it happened this morning, as the radar beam from the Langley Hill radar near Hoquium was bent to the ocean surface and was reflected back, creating a false echo that suggested offshore precipitation (see below).  No precipitation was there.

Finally, what about air quality?  Normally, inversions produce poor low-level air quality, since inversions suppress vertical motion in the atmosphere, allowing low level polution to concentrate.

Here are the latest air quality maps over the region.  Generally good air quality except for an area in the South Sound.

But why?  Inversions can suppress vertical mixing, allowing pollutants to concentrate.

According to an associate of mine in the Puget Sound Clean Air Agency, the relatively warm temperatures (high around 60F) today result in less burning of wood, a prime emitter of particulates.    And, of course, there are no wildfires going on this time of the year.

The warm surface temperatures during the day also weaken the inversion at low levels, improving air quality.

The End of Northwest Cold for The Winter and A Short Heat Wave

There comes a point each winter when it is simply not possible to get really cold anymore.

Here in the Pacific Northwest, we are now crossing that line.

The figure below shows observed temperatures at SeaTac Airport so far this year as well as the daily record highs (red lines) and lows (blue lines) for the entire year.  The brown band shows the average daily range throughout the year

Our temperatures so far this year have been quite normal, with warmer and cooler days.  

But now look at the cold records.  In January, record temperatures have dropped below ten degrees on many occasions.  But past the first few days in February, there is an abrupt jump to warmer temperature records, with record lows never getting below 15F.

By early March, we never get below roughly 25F.  

East of the Cascades at Yakima Airport, the situation is similar, except that the temperatures are much colder.  After early February, sub-zero temperatures are history!

The key driver of the transition to warmer temperatures is that the sun is getting stronger and days are getting longer.  You can see this in the plot of solar radiation reaching the top of the atmosphere over the year (below).  

The sun now is about the same as it was in early to mid-November.

 Talking about warmth, according to the highly accurate weather.com prediction, tomorrow through Friday should rise to near 60F at SeaTac.

But if you are willing to take a short drive, you may be able to experience 70F!

Where? In the western foothills of the Cascade!

High pressure has built over our region and will be in place overnight (see the upper level map--at 500 hPa pressure..about 18,000 ft for tomorrow morning).    High pressure results in warm temperatures aloft.

Tomorrow, low-level easterly (from the east) winds will develop that produce sinking on the western slopes of the Cascades, producing additional warming by compression.

As a result, there will be a band of uber-warm temperatures on the slopes in areas such as North Bend.  A UW model temperature prediction at 1 PM shows the warm zone.

A similar, if not stronger, warm zone will be apparent on Thursday (see below), with powerful warming on the western side of the Olympics tomorrow.

There are a lot of weather enthusiasts/weather chasers in our area.  Will one of you take a hike up Tiger Mountain or Mount Si tomorrow, making temperature measurements every few hundred feet?

I will add it to this blog if you give me the information!

High Pressure Danger: Fog and Roadway Collisions

This winter, persistent high pressure has frequently developed over the western U.S.

High pressure that has often brought dry conditions and afternoon sun.  But such high pressure also results in extensive fog, particularly in valleys and basins.

Fog is a serious threat with such high-pressure conditions, often resulting in multi-vehicle collisions, injuries, and loss of life.

For example, yesterday there was a 49-vehicle chain collision in the Central Valley of California between Bakersfield and Fresno as a result of dense fog.

Below is a visible satellite image from yesterday morning, which clearly shows the fog. 

 Such fog in the Central Valley is known as Tule Fog (named after the Tule grass that is extensive over the region).

Fog accident events often progress in a similar way.   

A collection of vehicles is driving too fast for conditions.     The first vehicle in the "pack" enters the fog and hits the brakes suddenly, setting off a chain reaction behind that car that can involve dozens of vehicles.

Washington State is home to many of such fog related accidents associated with high pressure.

Low-level fog is frequently present during high-pressure periods during winter in eastern Washington, with a long list of vehicle pile-ups during the "fog season" from November to February (see satellite image example below on January 17)

For example, a 38-vehicle pile occurred on I-90 near Kittitas on December 7, 2022 (see below).  I could list a dozen other such chain accidents associated with fog over the Columbia Valley.

The danger of such fog events are inceased during cold weather, when freezing fog makes roads slippery and dangerous (according to the 2022 event).

As mentioned earlier, these west coast events are often associated with high pressures aloft, as shown by the upper level (500 hpa, about 18,000 ft) upper level map for yesterday morning.  In meteorological parlance, we call this a ridging situation.

High pressure aloft reduces upper-level clouds, allowing the surface to radiate heat to space, and allowing the surface to cool to saturation (producing fog).   The high pressure aloft is also associated with sinking air that warms by compression aloft.  

Warming aloft and cooling near the surfae produces stable, inversion conditions, which are favorable for fog.

Finally,  the Northwest is one of the foggiest locations in the U.S., so being cognizant of the threat of fog while driving is important.

Mid-Winter Precipitation Review

We are now solidly into mid-winter--a good time to check on the status of precipitation over the region.

Let's start with the total cool-season precipitation since October 1, the beginning of the "water year" (see below).

The majority of the western U.S. has received above-normal precipitation, with the North Cascades and the Los Angeles area being substantially wetter than normal.

There is one major dry area:  western Oregon.

There has been enough precipitation east of the Cascade crest so that the Yakima Reservoir levels are not only WAY above normal, but GREATER THAN THE HIGHEST AMOUNTS of last year (see below).  Wow.

Temperature is a contrasting story (below).  

Much warmer than normal over the Rockies,  and near normal over western Oregon and the interior valley of California.  Modestly warmer than normal over much of Washington.

The key driver of these patterns of precipitation and temperature has been persistent high pressure aloft over the western U.S, and the persistent trough of low pressure aloft over the eastern U.S.    This is illustrated below, which shows the difference from normal at 500 hPa (roughly 18,000 ft).  Higher than normal pressure is indicated by the yellow;   blue and purple indicate the oppoosite

High pressure is associated with sinking and warming aloft.  It also contributed to dry conditions.  

The complex distributions of precipitation and temperature have created an even more complex distribution of snowpack over the western U.S.

The southern Sierra Nevada is fine, and eastern Washington and the Rockies are just a little below normal.

But the real problem area is found over Oregon and northern CA, where the combination of a lack of precipitation AND warm temperatures has resulted in snowpack areas below 40%.

Looking forward, the latest European Center forecasts are predicting substantial precipitation along the Washington Coast, over southwest BC, and the north Cascades.

But far less to the south, where the real deficiencies exist.

Oregon folks should not panic yet.  

I can remember a number of years that were dry until early February, but made up most of the deficiency in late winter and spring.

An Extraordinary Inversion, Twinkling Lights, and the Return of Rain

This morning, an extraordinary low-level inversion (temperature increasing with height) developed over the western Washington lowlands.

For example,  at 4 AM, the temperature around SeaTac Airport rose from 41F to 56F (15F increase!!) between the surface and 1000 ft.

You could see the large temperature variations at the surface, such as in this plot of the minimum temperatures this morning, with temperatures ranging from 29 to 53F.   Just amazing.

The extreme temperature change in the inversion produced an atmospheric lens that caused lights to flicker when viewed from above.

To illustrate, there is a video taken from above the inversion by Peter Benda, who lives at high elevation in the hills above Bellevue.

The inversion was associated with a transient area of high pressure, which now moved to the east.

In its wake, precipitation has FINALLY moved in, as noted by the latest radar image:

Weather forecast models are predicting one rain event after another during the next few days, with the heaviest amounts in southwest British Columbia and northwest Washington (see totals through Friday afternoon below).

You will need to find your umbrella😊

Cold Temperatures Hit Western Washington

Well below-normal minimum temperatures were evident across the state this morning.

Most of Washington was below freezing, with teens and single digits over eastern Washington and twenties and a few teens over western Washington.  

Below are the sub-20 locations in western Washington.   Hard freeze.  

What always impresses me in these situations is the local contrasts.  This morning's lows ranged from 35F near the water to 18F at Carnation.  Being away from the water makes a huge difference, and cold air (and often fog) drains into the Snoquamie Valley.  

The cold air that reached us is only a small taste of the amazingly cold air that has descended into the central and eastern U.S.

Consider the forecast temperatures for 7AM PST this morning (below), with purple and blue indicating the coldest.

The Rockies are our key line of protection, with an enormous temperature contrast across the southern Rockies.

As cold as this morning was across western Washington, no records were being made.  To illustrate, here are the temperatures in Ollymc this month (blue bars), with the average range in brown and the cold records in blue.   We have been below normal, but not even in the vicinity of daily records.

An irony of the cold is that renewable energy, and particularly wind energy, has gone to nearly zero in our area, just as we need it for heating--something that is quite typical.   

Consider the latest BPA statistics below.  Renewables (mainly wind) are nearly flatlined around zero.  Our limited nuclear power (purple) is steady and significant.   Thankfully, we have a lot of hydropower.

You can see why I am a strong supporter of nuclear power (fission) and the development of fusion power. 

Tales of Two Slopes: Hot and Cold

There has been a lot of talk about warmth in the mountains, loss of snowpack, and inversion conditions.   

The truth is a bit more complex.  

The western side of the Cascades has been warmer than normal with significant loss of snow, but conditions have been MUCH cooler on the eastern slopes, helping to maintain snowpack on that side.

Let's explore the fascinating temperature variations of the past few days.

Below are the minimum temperatures on January 16th and 19th.

Forties on the western slopes of the Cascades, but below freezing east of the crest, with many locations in the teens.

As I have discussed in prior blogs, a pool of very cold air has been trapped in the Columbia Basin, with cold air associated with a low cloud deck of stratus and fog (see the satellite picture below).

The UW high-resolution modeling system accurately simulated this cold/warm pattern.  

For example, the model forecast for the surface (2-m above surface) temperatures at 1 PM Saturday shows warmth (red colors) on the western Cascade slopes up to the crest level, but colder air right over the crest (blue and green colors).

Note the warm temperatures on the western slopes of the Olympics and coastal mountains as well.

Next, consider the temperatures at some locations on both sides of the Cascades. 

 At Paradise (Mt. Rainier) at 5000 ft on the western slopes, the temperatures (blue bars) were well above normal (brown band) during the past week..

In contrast, it was much cooler at Holden Village on the NE slopes of the Cascades. A short period of warmth followed by normal and colder than normal conditions.

The impacts on snow melt on both sides of the Cascades were noticeable.

On the west side of the North Cascades, the Upper Skagit snow water amounts are 89% of normal and have declined during the past week.

In contrast, the Methow drainage on the eastern Cascade slopes is a 124% of normal and holding steady!

The critical snowpack on the eastern side of the Cascades, so important for agriculture, is being protected by Columbia Basin cold!