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.

Fog and Freezing Fog in the Inland Empire: Intense Inversion Aloft

The Columbia River basin is well known for sun and warmth for much of the year, compared to the sodden, cloudy western side of Washington State.  

During the cool season from mid-November through mid-February, the reality is often different, with cool, cloudy air trapped within the basin, often producing fog and FREEZING fog.

The last few days are great examples of this chilly, fog-laden situation.

Consider the visible satellite image around noon today (Friday). Clear over most of western Washington and Oregon, with the Columbia Basin full of stratus and fog.

Checking on the Washington Department of Transportation webcams, on the eastern side of the Cascades, Kittitas was in fog:

And Yakima was not better. Much of this fog was of the freezing variety, a great danger for ground transportation.

Not surprisingly, my colleagues at the National Weather Service had dense fog and freezing fog advisories out last night (see below).

To appreciate the cold and unpleasant nature of the old air trapped within the Columbia Basin, below is a plot of the maximum temperatures today around the state.

Yikes.  Much of the Columbia Basin never got out of the mid-30s.    Some locations never rose above freezing.  In contrast, lots of 50s in Western Washington and some very warm conditions in the mountains (Cascades and Olympics). 66F in the Olympic.

Why so warm in the mountains? 

Because a strong inversion (temperature increasing with height) was created by the high-pressure system aloft (see the upper level map for 4 PM Thursday below).

High pressure aloft causes sinking and warming aloft, with descending air warmed by compression (like when you pump up a tire!).  The sinking decreases as one approaches the surface (air can't move downward through the surface).  Thus, temperatures remain cool at low levels, which is further chilled by the emission of infrared radiation to space.

There is a world-class inversion above us today.    To show this, below are temperatures above SeaTac Airport at 8 PM, measured by aircraft landing and taking off.

Unbelievable!  Low 40s near the surface and nearly 59F at 1400 ft.    Take a hike tomorrow morning.  You will not believe how temperatures warm with height.

Consider the situation on the slopes of Tiger Mountain in Issaquah.  At the Tiger Mountain Family Nudist Park, the temperature was 40F, but up on the slopes below Poo Poo Point (about 1500 ft), it was 57F!   

My pro-tip for the nudists is to take a hike up the hill before removing their clothing!

Super Dew

Last night, I was struck by how wet some surfaces were...without any rain.

For example, here is an area of a brick patio around 6 PM...quite wet.

The origin of this wet bounty was the very moist air over the region, with dew points rising well into the fifties.   At the same time, the weather had been relatively cool, allowing the ground surfaces to cool below the dew point.

Dew Point 101

The dew point or dew point temperature is the temperature at which water vapor starts to condense as the air cools.

So when the surface temperature declines below the dew point, water vapor condenses onto the surface, producing a wet sheen.

Yesterday, a plume of warm, moist air from the subtropics caused local dew points to climb.

Below are the dew points around noon yesterday.  Many were in the low to mid-50s.

A plot of the dew point at Boeing Field (ending yesterday evening) illustrates that the dewpoint yesterday was the highest of the winter so far,  reaching nearly 55 F.

Ground temperatures were relatively cool after a fairly cool late December, with temperatures at SeaTac shown below (the blue line shows the daily range. 

 In general, temperatures were below 50F, allowing surfaces not in direct sunshine to cool to that or cooler temperatures.  That means dew.

Soil temperatures in Seattle near the University of Washington are shown below.  Generally below 50F.

So, with a cool surface and moist air, abundant condensation occurred, something that was apparent if one looked around.

Finally, some folks have expressed concerns about air quality under high pressure.   

At this point, there are no issues, with the latest vertical sounding over SeaTac not indicating any low-level inversion (with temperature increasing with height).  Inversions trap low-level pollutants.

And air quality measures are generally quite favorable (low), as indicated by the green dots below.  You can breathe easily.

One Day "Heat Wave" Followed by a Week of Dry Weather

 If you have an umbrella, put it away...you won't need it for a while.

 Find your sunglasses...you will need them.  

A major mid-winter break from the rain and murk has now begun...and tomorrow, Tuesday, will be the warmest day of the period.   Some locations will even get to 60°F, but perhaps not where you would expect it.

Consider the forecast surface air temperature at 2 PM tomorrow over Washington--close to the time of warmest temperatures in winter (shown below).

Western Washington is warm, with some locations reaching the upper 50s...and some lucky folks into the lower 60s.

Since such warmth is so attractive this time of the year, here is a close-up map at the same time.  Head north and east of Seattle!

I know what you are wondering.  Can you trust this forecast?  

Good question...particularly after the disastrous forecasts of a big windstorm last week.  As I have discussed before, we need to consider the multiple predictions using ensemble systems, and the UW has one of the best.

Here is the prediction of the many forecasts of the UW system for Seattle.  Nearly all are on board for the warmth.   You can bank on this one-day wonder.

We will cool off after tomorrow, but persistent upper-level high pressure will move in, with at least a week of totally dry weather.  To show this, below is the ensemble of many forecasts of precipitation in Seattle from the NOAA/NWS GFS model.

Precipitation is flatlined at least through January 20.  Other forecast systems are doing the same thing.

Interestingly, long-term climatology shows that amid-month drying is not unusual.  To illustrate, here is the climatological probability of receiving at least 0.10 inches at SeaTac in a day.  You will see a drop in mid-January.

But don't worry, extended model forecasts show the precipitation coming back.   

And if I were irresponsible, I would show the forecast total snowfall by the end of the month.

A forecast that shows lots of snow over the western lowlands.  It would get lots of clicks and attention.   

This is the graphic I am not going to talk about, so please don't look at it and don't talk about it on social media. 😁