JACKSON, Wyo. – An unseasonably warm airmass has taken hold across the Western U.S. this week, and Jackson is forecast to break multiple daily high temperature records through Saturday. The all-time monthly record high for March of 70ºF is also in jeopardy.
Recent Weather
Last week, we were on the southern fringe of a strong and persistent jet stream that favored heavy precipitation across the Pacific Northwest, and only a few glancing blows for the Tetons.
Instead, we experienced consistent cloud cover and consistent strong winds, with seven straight days from March 8-14 in which a wind gust of at least 50 mph was recorded at the top of the tram at Jackson Hole Mountain Resort.
During this windy streak, there were also seven days in a row with a wind gust of at least 30 mph at the Jackson Hole Airport, and five of these seven days had a gust of at least 40 mph.
Saturday, March 14 was the windiest day of all in which gusts of 55 mph were recorded at the Jackson Hole Airport and 75 mph at the top of the tram. Also, the Surprise Pinnacle weather station in Grand Teton National Park at 9,770 feet recorded a gust of 122 mph!
Snowfall has been very spotty across the Tetons over the past seven days, ranging from 3-14 inches above 8,000 feet, with the highest totals recorded at Surprise Meadow in Grand Teton National Park.
The valleys received only brief and light dustings of snow over the past week, along with light rain.
Temperatures were generally mild, but also very back and forth in this pattern. A cold front did move through on Saturday, resulting in a chilly weekend with a high of only 33ºF in Jackson on Sunday, though the sun did come out, and winds finally calmed down a bit.
Since then, a strong ridge of high pressure has been building over the Western U.S. and temperatures have warmed up significantly. On Tuesday, the high in Jackson hit 63ºF, which was 30 degrees warmer than the high temperature from two days ago.
The 63ºF high was recorded at the JKNW4 weather station in Jackson, while the long term COOP station reported a high of 62ºF, which officially set a new daily record.
Below is a 7-day weather summary for the town of Jackson.
For perspective, the average high and low in Jackson on March 18 are 43º and 19º.
Snow depth in the Tetons is, surprisingly, around 95% of average above 9,000 feet on the east side of the range and around 80% of average at 8,000 feet.
However, below 7,000 feet, snow depth ranges from 0 to 20% of average and is near historical minimums. The lower valleys have largely been melted out for weeks now.
The ongoing warm spell is going to be a major dent in the snowpack with significant melting expected, even across the higher elevations.
Upcoming Weather Pattern
The big story over the next week will be the record-setting warm spell. We are already seeing some low 70s around the town of Jackson on Wednesday afternoon. It remains to be seen what the official high temperature will end up being today.
But there is a chance that Jackson has tied or broken its all-time high temperature record for the month of March. The current all-time high temperature record for the month of Jackson is 70ºF which was set on March 31, 2004.
If a 70-degree high temperature is confirmed for today, it would be the earliest 70-degree day on record in the town of Jackson by nearly two weeks!
Thursday to Saturday will also be unseasonably warm, and we will have a chance of matching the all-time record again with highs projected to reach the upper 60s to low 70s each day. Daily high temperature records this week are in the low to mid 60s, so we should easily break more daily records.
Heading into next week, the warm spell will relent a bit, but it will still remain warmer than average overall.
First, a cold front will move through on Sunday, which will knock highs down into the 50s. We could see a few showers move through, but it looks minimal at this point.
Warmer temperatures are expected to return by early next week, then around the middle of next week, there is another chance of rain/snow showers, but nothing significant is expected.
We may see a stronger cold front arrive around the middle of next week that could cool us off briefly, but then highs are projected to warm back up well into the 50s again by the weekend of March 28-29.
Snowfall potential over the next 7 days, and even the next 10+ days, looks marginal for the Tetons right now.
It’s safe to say that at this point, we are not going to see any major late-season winter comebacks this year. Even if we get some good snow events in April, new snow at that time of year typically doesn’t stick around for long.
Heading into the spring and summer, confidence is growing that El Niño conditions will develop in the Pacific Ocean, with a strong El Niño episode possible.
Seasonal outlooks are never a sure thing, and every year is unique. But it’s worth pointing out that there is a connection between emerging strong El Niños and above-average late spring to summer rainfall in the Greater Teton-Yellowstone Region (the most recent examples being 2023 and 2015). That would certainly be welcome this summer in terms of water, drought, and fire conditions on the heels of a lackluster winter.
Alan Smith, Meteorologist
