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!

The Driest Winter Period in Northwest History?

 It hasn't rained (or snowed) in a week.  Next week will also be dry.

Dry in Washington State.  In mid-winter.

Is this the driest mid-winter period in the history of our region?

According to the National Weather Service, the last rain fell in Seattle on January 12th:

And considering the highly skillful European Center forecast, the first rain won't be until January 26:

That is 13 days without precipitation for most locations in western Washington, during the middle of the winter!

Thirteen dry days.

How unusual is this for midwinter (we do this all the time during summer)?

Let's check the numbers for the Northwest wet season (November 1-February 28)

Below is a list of other periods when Seattle has had no precipitation for 13 days in mid-winter: FIVE other years (2005, 2002, 2000, 1993, and 1985).

 What about times when Seattle had only a trace of precipitation over 13 days (a trace is when less than  0.01 inches fall)...something that can be done by a light mist?

Several other years are added.  2025, 1989, 1968, 1963, and 1956

Finally, considering years when only 0.01 inches of precipitation fell (a trace of rain...just enough to make a surface wet), we add 2013, 1994, 1989 (twice), 1976, 1974, 1992, and 1945.

The bottom line of this analysis?

Since 1945 (81 years), we have had 13-day dry periods (0.01 inch or less) about 20 times.  

So it has happened before, roughly once every four years.

Such dry years are scattered over the period and don't appear to have an obvious increasing trend.   This is not climate change.

The current dry period is expected to end, as indicated by the predicted precipitation through February 5 (see below).   

So enjoy the sun while you can.  

I know some folks who are going to be happy with the return to wettness.

Global Warming is Only A Modest Problem

Human-forced global warming (also called "Climate Change" by some) is only a modest problem.   

The scientific facts are clear:

It is NOT an existential threat to humanity.   It is NOT a crisis.

Huge amounts of money are being wasted (such as the unfortunate Washington State Climate Commitment Act), governments are putting great efforts into non-productive activities, and people are suffering unnecessary anxiety and fear.

Why should you at least consider what I say on this topic?  

 I have published dozens of papers on climate topics.   I  studied with and published with one of the leading climatologists of the past century (Steven Schneider of NCAR and Stanford).  When Jay Inslee (then a congressman) sought a tutorial on climate change, he came to me. I have received several NSF grants to work on climate topics.

Climate "Journalism" at the Seattle Times

Let's consider a few of the unfounded claims of climate activists.  

Extreme Weather, Enhanced by Climate Change, Is Causing Increasing Numbers of Deaths

You have heard the claim multiple times:   increasing extreme weather resulting from climate change is resulting in many more extreme weather-related deaths.

This is simply untrue.   Deaths from extreme weather (extreme heat/cold, hurricanes, extreme windstorms, flooding, etc.) are down...a LOT (see proof below).

Such deaths are down even though there are a lot more people on the planet.  

Why?   Much better forecasts allow people to get out of the way or prepare.  Many nations have invested in making themselves less vulnerable to severe weather--including some of the poorest.

Want an example?  In 1970, Cyclone (Hurricane) Bhola hit Bangladish and nearly 500,000 people died.

In 2020, a more powerful storm (Super Cyclone Amphan) hit virtually the same location, with only 133 deaths.

Severe storm deaths are profoundly down.....is this a "crisis"?

What about Northwest flooding and heavy rain?  

Average rainfall over the region is not increasing; if anything, it is level (see SEATC annual precipitation.

Winter daily extreme precipitation is up slightly (see sample for SeaTac below)

Regional climate models suggest a small decrease by the end of the century (the change in the annual highest 5-day precipitation is shown below)

There is little reason to expect more severe flooding over Washington State by the end of the century. 

 With better management of our rivers and development, there could be LESS flooding even with the very modest increases in precipitation.

Extreme Temperature Deaths Will Decline

There is a deep literature showing that cold waves kill far more people than heat waves.   For example, a 2015 article in The Lancet found 17 times more deaths from cold than heat (see figure from that article below).

Thus, global warming will REDUCE deaths from extreme temperatures.  

Furthermore, it is generally much easier to protect from heat than cold, with air conditioning being effective for taking the edge off of generally shorter head waves, compared to the extended cold waves that result in most of the deaths.

Northwest Snowpack

Global warming is causing the region to slowly warm, which will cause a slow decline in snowpack.  A very slow decline.  

As shown by the data, Washington State has warmed by about 1°F over the past 125 years during the winter snow accumulation season (October through March).  Human greenhouse gas emissions were the key contributor to the recent warming.

This modest warming has only produced a very small decline in April 1 snowpack at the official (SNOTEL) observing sites (Figure below produced by past Washington State Climatologist, Mark Albright)

High-resolution regional climate models suggest a continued slow decline in Northwest snowpack, dropping by ~15% by mid-century.  Not the end of the world.

Wildfires

Probably the most irresponsibly hyped aspect of global warming is the connection with wildfire.    The truth is that human alteration of the surface, increasing population, and human ignition of fires are FAR more important than climate change.  

Consider a plot of wildfire acres burning across the U.S. (below).  A LOT more fire acreage a century ago, when global warming was very small.

Considering only Washington State during the past ten years...a period when global warming was supposedly the greatest... wildfires are actually down.

The truth is that human ignition and wildfire management are central.  That human modification of the surface is critical....and far more important than climate change.   

The development of the technology of fire suppression and the funding of a massive suppression infrastructure led to a big drop in fires during the middle of the 20th century.  

Human mismanagement of forests and human introduction of flammable grasses contributed to the recent modest fire increase.  There has a huge increase in human ignitions (e.g., powerlines and arson) and the massive intrusion of flammable structures into the wildland/urban interface.

Warming temperatures are a very minor contributor to the modest increases in wildfires during the past decades.

Sea Level Rise?

Sea-level is slowly rising with NO acceleration as claimed by climate activists.  Here is the long-term trend at Seattle--about an 8-inch rise over a century.   Very typical of locations around the world.

Climate Economists Set the Record Straight

There have been a number of studies of the impacts of global warming on the world economy.   The general conclusion:  even unfettered global warming would only have a very small impact on economic growth across the planet.

Without or without global warming, humanity will be immeasurably richer and better off by the end of the century.

William Nordhaus, who received the Nobel Prize for his analysis, found that even unfettered global warming would decrease global economic growth by a few percent.  The entire world will be MUCH richer and healthier by the end of this century, even with global warming.

Willian Nordhaus

Final Words

Why are so many groups hyping and exaggerating the impacts of global warming?  Claiming disaster and existential threats without a factual basis.

For some, it may give them the satisfaction that they are "saving the world", giving meaning to their lives.

For others, it may be a political tool to undermine the opposing political party.  Or a way to gain political power (e.g., certain prior governors)

For others, it may be a way to gain money and resources.  The Washington State CCA is a poster child for such greed.

Whatever the reason, climate change hype and exaggeration are both destructive and counterproductive, often hurting the very people advocates claim to be concerned about.