JACKSON, Wyo. – The town of Jackson’s long-term weather station set a new high temperature record for the month of March last week, and also recorded its earliest 70-degree temperature on record, beating the old record by 12 days.
Recent Weather
Spring has come early to Jackson Hole this year, and some might argue that winter never really set in.
We were already in the midst of the warmest winter season on record across Wyoming and the Western U.S. prior to last week. But the warm spell experienced over the past week has been particularly extreme.
A strong ridge of high pressure set up over the Western U.S. last week, and this high-pressure ridge was more than 3 standard deviations above average for this time of year, meaning it was above the 99.7th percentile for this time of year historically.
The COOP weather station in Jackson, with records dating back to the early 1900s, recorded its earliest 70-degree temperature on record on March 19. The previous earliest 70-degree day occurred on March 31, 2004, and the high temperature of 70º on this date was the previous all-time record high for the month of March.
On March 20 and 21 (last Friday and Saturday), the Jackson COOP station reached a high of 71º on both days, which is now the new all-time high temperature record for the month of March. The JKNW4 weather station in Jackson was even warmer with a high of 72º recorded on March 20.
Below is a 7-day weather summary for the town of Jackson (JKNW4 weather station).
For perspective, the average high and low in Jackson on March 25 are 45º and 21º.
Jackson was not the only location that saw all-time record warmth for the month of March. These records were widespread across the state of Wyoming and across the Western and Central U.S.
Here is a list of locations across the Western and Central U.S. that set all-time high temperature records for March last week. Some of the temperature readings are hard to fathom at this time of year, such as 100s in the Southwest U.S. and mid to upper 90s as far north as Nebraska.
Even in Wyoming, Lander recorded a high of 82º and Casper a high of 83º!
Snowpack has been on a rapid decline in the Tetons as a result of the warm and dry weather, even across the higher elevations.
On average, snowpack (the depth of the snow on the ground) reaches its deepest levels near the top of Jackson Hole Mountain Resort on April 9. However, this year peak snowpack occurred on March 11, nearly a month earlier than average. And snowpack has been declining ever since.
Currently, snowpack is 77% of average at 9,000-10,000 feet, 60% of average at 8,000 feet, and at record low levels across the lower elevations.
The Moran weather station near Jackson Lake has already melted out, which is the earliest such instance on record, with data going back to 1949. The previous record low snow depth value for March 25 was 10 inches in 2004, and the average snow depth for March 25 is 35 inches.
The chart below shows current snow depth in blue and average snow depth for the date in green, with the percent of average value displayed above each pair.
The current snow depth at Jackson Hole’s upper mountain is the second lowest for the date in the last 15 years, with only 2022 coming in slightly lower.
The current snow depth at Jackson Hole’s mid-mountain is the lowest for this date since 2010 and the third lowest on record since 1975.
Despite the poor snowpack numbers, amazingly, water year precipitation (since October 1st) remains slightly above average across the area, which shows just how much the warmth has impacted snowfall and snowpack this season.
Upcoming Weather Pattern
Wednesday has been another warm day with highs well into the 60s, though we’ve seen enough cloud cover that it may prevent us from hitting 70 in town again like we did last week.
A weak cold front will move through on Thursday morning, which will cool things off slightly, but it will still be warmer than average with highs in the mid 50s on Thursday and near 60 on Friday.
Unseasonably warm temperatures will return from Saturday to Monday with highs in the upper 60s in the valley, and another run at 70º is also not out of the question.
Despite this prolonged warm and dry spell, confidence is growing that we will get at least somewhat of a reality check next week as a slow-moving trough of low pressure approaches our area.
The result will be a cooling trend along with a good chance of snow and rain, including the potential for respectable snow totals at the mid to higher elevations.
An active pattern is also projected to continue through the first week of April, with above-average precipitation favored and near-average temperatures favored.
This means there is potential for multiple rounds of high-elevation snow with travel impacts possible over Teton Pass. Hopefully, you haven’t put away your snow tires for the season yet!
For perspective, average highs during the first week of April in Jackson are in the upper 40s, while average highs above 9,000 feet are in the low 30s.
During the month of April, the upper mountain plot at Jackson Hole Mountain Resort averages 58 inches of snowfall, and even the town of Jackson averages 5.6 inches of snowfall.
In other words, it’s normal to see winter weather from time to time in April, especially up high. It’s just that fresh snowfall tends to not stick around for very long at this time of year, especially in the valley.
Alan Smith, Meteorologist.
