All posts by Jim Woodmencey

Weather History of Jackson Hole

Click on the image to view the You Tube video of this presentation by meteorologist Jim Woodmencey for the Geologists of Jackson Hole in February of 2023.

 

 

 

 

Introduction:

Meteorologist Jim Woodmencey has lived and worked in Jackson Hole since 1982 and has forecast, studied, and written about Jackson Hole’s weather for over 30 years.

This presentation explores Jackson Hole’s weather history, beginning with when the earliest weather observations began, to where our local climate stations are located. It will also discuss how those observations are recorded and what has changed over the years, both in instrumentation and station location.

From all the available weather data, spanning about 100 years, we can construct a historical picture of the averages and the extremes of weather that have occurred in the Jackson Hole Valley. What were the hottest and coldest temperatures ever recorded? When was it wettest or driest? What were the biggest storms and the biggest snowfalls?

The distinction will be made between what is weather and what is climate and how they are connected. It is from all the daily weather observations that are recorded over time that we establish our averages, or what we consider to be “normal” conditions. It is those averages by which we judge the trends in our local climate.

A complete picture of Jackson’s entire weather history is presented along with the current trends in temperature, precipitation, and snowfall. So, if you lived in Jackson Hole for a lifetime or just a few years, this presentation should provide you with a more comprehensive perspective on both the weather and climate of this unique location.

 

Did the Planet really have its Hottest Day Ever? No.

 

News headlines around the globe last week proclaimed that July 4th, 2023, was the hottest day ever recorded on Earth. Some of those headlines read: “Planet’s temp hits new high”, “Earth’s hottest day in recorded history”, “Alert: The hottest week on Earth”.

Temperatures apparently broke the record four days in a row, from July 3rd to July 6th. Oh my, that’s alarming, especially since it is only early July and our warmest days, in the Northern Hemisphere at least, are yet to come this month and into August.

If you were to look under the hood though and read past the headlines, you would discover that these temperatures were “unofficial”.  And the data set used only went back as far as 1979.

The data used to make those proclamations was generated from a computer model run at the University of Maine. The model, known as the Climate Forecast System Reanalysis (CFSR), incorporates temperature readings from land surface stations, weather balloons, satellite measurements and ocean buoys to arrive at an estimate for the planet’s mean temperature at hourly intervals throughout any given day.

Not so Fast

On July 6th, 2023, the National Oceanic and Atmospheric Administration issued a note of caution about the University of Maine’s findings, saying it could not confirm data that is in part a result of computer modeling.

“Although NOAA cannot validate the methodology or conclusion of the University of Maine analysis, we recognize that we are in a warm period due to climate change,” NOAA said.

NOAA also noted that the reanalysis data was “not suitable” as a substitute for actual temperatures and climate records.

Actual temperature records from NOAA’s Global and United States Historical Climatology Networks (GHCN & USHCN) date back to 1895.  For the lower 48 U.S. states, where the majority of stations with the longest records are located, NOAA’s data shows that it was much warmer in the early 1900’s.

NOAA’s data shows that the percentage of days above 90 degrees F, annually, at all U.S. stations, has been declining (Graph 1). The peak of the heat occurred back in 1936, with 15 percent of the days that year at all US stations above 90F. This provides further evidence that  HOTTEST DAY EVER on the planet occurred this July even less feasible.

Graph 1: Percent of Days annually above 90 F at all US Stations

A different analysis of USCHN temperatures showing the Percent of Stations that got above 95F for the date July 3rd, which is the first day of the supposed new record high temps. This graph below (Graph 2) shows that July 3rd in 2023 only ranked as the 49th warmest July 3rd in the last 128 years in the United States. That makes it hard to believe that the rest of the world could somehow propel the planet to the number one spot this July.

Graph 2: Percent of US stations above 95 F on July 3rd. Ranked in order of  most to least. July  3rd, 2023 ranked as #49.

Heat Waves & Record Highs

Granted, there have been some brutal heat waves these past couple of weeks around the country and in certain parts of the world, but it was not the hottest ever. At the same time, there have also been areas of the globe that were much cooler than average.

In the United States, records dating back to the late 1800’s and early 1900’s show the Heat Wave Index has been fairly steady, with the biggest spike and warmest period of time ever in the US occurring in the 1930’s, during the Dust Bowl. Many of the all-time highest temperature records from the 1930’s still stand today. (Including The Town of Jackson, WY, when it was 101 degrees F in July of 1934)

This graph shows the annual values of the U.S. Heat Wave Index from 1895 to 2021. These data cover the contiguous 48 states. An index value of 0.2 (for example) could mean that 20 percent of the country experienced one heat wave, 10 percent of the country experienced two heat waves, or some other combination of frequency and area resulted in this value. Data source: Kunkel, 2022, EPA https://www.epa.gov/climate-indicators/climate-change-indicators-heat-waves

Note: When viewing the EPA site, the graphs on the page this link opens to on Heat Waves shows bar graphs that only go back to the 1960’s. You have to click on the link for Figure 3, Heat Wave Index to see the graph shown here.

Latest Daily Records

NOAA’s database of daily weather records across the United States also shows that in the last 30 days (from June 9 to July 9, 2023) there were 672 record high maximum temperatures set. At the same time, there were nearly twice as many low maximum temperature records established, 1,221 of them. There were also 991 record low minimum temperatures set in the last 30 days. (See the data below).

Data table updated on July 9th, 2023

Alas, cold temperatures don’t make headlines these days. Unfortunately, the story that the Planet was “hotter than it has ever been” this July will become the catchphrase and taken as scientific gospel going forward. Even if the data used was unofficial, incomplete, and misleading.

Additional Info to Add…from others

Some people, such as Ryan Maue, Ph.D., tried to put out the wrongheaded social media fire on Twitter. He notes that the climate model used isn’t even current, circa 2009/2011:

It seems the media, social and otherwise, saw what they expected to see and got fooled. They failed to check the source of the data before rushing to judgment.

The graphic below shows the big “heat source” that caused the panic – an apparent glitch (or short term outlier anomaly) in model output that made it look like the waters off Antarctica were boiling hot, and when “averaged” over the entire globe, made that false 17°C uptick.

It isn’t even an up to-date climate model, circa 2009/2011 and is not an official NOAA or NCEP climate modelling product.

Some Additional July 4th Graphs of Temps

Below are couple of other graphs worth considering. One shows the average maximum temperatures on the 4th of July each year at all US stations. The other shows the percentage of stations that that were over 100 degrees F on the 4th of July each year. Both have been slightly declining.

Average Maximum July 4th Temps

 

Percent of stations in US with temps above 100F on July 4th

You may note that the blue lines depict CO2 concentration, but I would tend to discount that line for this analysis because CO2 measurements in the atmosphere did not begin until about 1958.

Lastly, here is a short You-Tube Video from another scientist describing the misleading information: Hottest Day Ever

Jim is the chief meteorologist at mountainweather.com and has been forecasting the weather in Jackson Hole and the Teton Range for over 30 years.

Jackson’s Cold and Snowy Winter of 2022-23

One year ago, we were lamenting about a sub-par winter season. We had a big December for snowfall in 2021, then a lackluster January through March in 2022. Only to get dumped on by one of the snowiest April’s on record.

This year the story was a little different, snow started falling in late October and hardly let up for the next five months. Temperatures were also much colder than normal from November all the way through March, allowing the snow to accumulate to great depths, around the valley and in the mountains.

Colder and much snowier than normal was the scene across many areas of the Western United States this winter. Here I will highlight just how cold and snowy it was here in Jackson Hole, Wyoming

Cold Town Temps

It all began back in November, when Jackson had its coldest November ever recorded, with a mean temperature for the month of 17 degrees. That was 11 degrees colder than the long-term average temperature in November and it beat the old record from 1938 by nearly two degrees.

The cold temps never let up. December 2022’s mean monthly temperature was three degrees colder than the long-term average, January 2023 was two degrees colder than average, February 2023 was eight degrees colder, and March of 2023 ended up a full nine degrees colder than the long-term average temperature for March in Jackson.

From November 1st, 2022, through March 31st. 2023 the Town of Jackson recorded 65 days with minimum temperatures of zero degrees or colder. That’s 43-percent of the days over the past 5 months that we woke up to temps at or below zero.

The coldest day of the winter was on January 31st, 2023, when the official thermometer at the Jackson Climate Station registered 33 degrees below zero. The last time it was colder than that in town was on December 23rd, 1990, when it got down to 40 below zero.

That all adds up to a ridiculously cold winter and should toss any notions about global warming out the window, at least on a local scale. The much colder than normal temperatures of the past five months only added to the trend in Jackson of colder than average annual mean temperatures that we have seen over the last 10 years now.

Annual Mean Temperatures for all years with complete data

Big Town Snow

Total snowfall recorded at the Jackson Climate Station from December 1st, 2022, through March 31st, 2023, was 83 inches, compared to the average snowfall for that four-month period of 61 inches.

Last year the October through March snowfall total in town was only 56 inches. However, you may recall that April 2022 roared in with an additional 17 inches of snowfall in town, when traditionally April only averages around 4 inches of snow. April of 2022 tied for the third snowiest April on record in town.

Winter Snowfall Comparison Chart: December 1st through March 31st

If you add the snowfall from October and November of 2022 to the total, of one inch and 21 inches, respectively, then the total snowfall from October 2022 through March 2023 comes to 105 inches. That means, if you live in town, you had to shovel, blow, or plow almost nine feet of snow out of your driveway this winter.

That entire fall and winter season snowfall total of 105 inches is 148-percent of the town’s long-term average snowfall for October through March of 71 inches.

More info about the trends of colder and snowier in Jackson can be found in my blog post: Review of the Weather in 2022

Record Town Depths

Because of the colder than normal temperatures all winter long, snow on the ground barely had any opportunity to melt and settlement of the snow pack in the valley was minimal. During the first week in April the settled snow depth in town at the climate station was at 26 inches on April 3rd. That is the deepest snow ever recorded on that date in town, breaking the record on that date of 22 inches from 1985.

On April 5th, 2023 the settled snow depth was 24 inches, breaking the old record of 18 inches from 2008. April 6th also established a new snow depth record in town. The average snow depth during the first week in April in the Town of Jackson is between 4 and 5 inches. So, if you thought there was a lot of snow on the ground for this time of year, your observation was correct.

Record Mountain Snow

At Jackson Hole Mountain Resort’s Rendezvous Bowl weather station, at around the 9,600-foot elevation, the total snowfall for what I will call the ski-season, from December 1st, 2022, to April 1st, 2023, was 443 inches. That is 143-percent of the average snowfall for that four-month period at Rendezvous Bowl, which is 309 inches.

Total snowfall during last year’s ski season was 241 inches. December 2021 alone accounted for 112 of those inches and was the only month of last winter’s ski season that had above average snowfall. April of 2022 added another 79 inches of snowfall, but most of that fell after the ski area had closed.

Winter Snowfall Comparison Chart: December 1st through March 31st

In the bigger picture, the total snowfall recorded on the mountain from October 1st, 2022, to April 1st, 2023, was 572 inches. That was only four inches shy of the record snowfall from the winter of 1996-97, which had 576 inches of snowfall during that same period. That would make the winter of 2022-23 the second snowiest ever recorded on the mountain, for total snowfall between October 1st and April 1st.

Ranking of the Top-Ten Snowiest Winters, from 48 years of complete records.

However, if you include snowfall data through closing day, then the winter of 2022-23 surpassed was the snowiest winter ever recorded on the mountain, with a grand total of 595 inches of snowfall this season. That beats the 585 inches that fell during this same time period in 1996-97 and also the 590 inches that was recorded in the winter of 2017-18 from October 1st through April 9th.

Total Snowfall from October 1st through April 9th, for years with complete records.

Bottom-line is, no matter how you slice it, 8 out of the top 10 snowiest winters at the Jackson Hole Mountain Resort occurred in the last 15 years. Five of those top-ten winters happened within the last six years! The winter of 2021-22 was the only year in the last six that saw below average snowfall.

Mountain Snow Depths

Once again, colder temperatures made for lower density snowfall throughout this past winter. That made for great powder skiing and provided some of the best coverage, top to bottom on the mountain, than we have seen in years, since 2010-11 at least.

When the season ended on April 9th this year, the settled snow depth in Rendezvous Bowl was at 129 inches. Last year on April 9th, 2022, it was only 73 inches deep. Ten feet vs. 6 feet of snow depth at 9600-ft. The average depth on April 9th is 106 inches. The deepest ever on that date was in 2017, with 159 inches.

What made the skiing even better was the fact that snow depths at the base of the mountain stayed deep all winter also. I skied on closing day and did not see a single rock or bare patch of ground exposed on any of the major runs. That is not the usual case in early April.

Snow depths at the base of the mountain on April 9th, 2023 stood at 37 inches. Last winter, on April 9th, 2022, the snow depth was 9 inches. The deepest ever was in 2011, with 40 inches. The average snow depth on that date at the base is 21 inches.

A Unique Winter

What made this winter so exceptional was the fact that it was consistently colder and snowier than normal for five consecutive months, which made for very consistent skiing conditions all season long. So, if you like snow, this was truly a dream winter in every meteorological sense.

And to all those climatologists who have been making the same claim now for the past 20 years that, “within a few years, we aren’t going to know what snow is”, I would say, come spend a winter in Jackson Hole.

Jim is the chief meteorologist at mountainweather.com and has been forecasting the weather in Jackson Hole and the Teton Range for over 30 years.