JACKSON, Wyo. – November was slightly colder and drier than normal, and snowpack is below normal in the Tetons heading into early December. The pattern will remain dry through Saturday, December 7, then a storm is likely on Sunday, December 8.
November 2024 Recap
November featured a sharp transition to winter-like temperatures following a mild October, but snowfall was hit-or-miss as the majority of storms tracked too far north or south of our area. While we did see some decent snow events, we are off to a slow start to the winter season.
Temperatures ended up 1.1ºF colder than normal in the town of Jackson, while further north in Moran, temperatures were right around normal. In Jackson, the average high was 39.8ºF and the average low was 17.1ºF.
The highest temperature of the month was 57ºF on November 11 and the coldest temperature of the month was 0ºF on November 20.
Across the West, temperatures were colder than normal from Jackson Hole southward, and a bit above normal further north. Also, most of Western Wyoming was colder than normal, while areas east of the Continental Divide in Wyoming were warmer than normal.
The town of Jackson only received 0.89 inches of precipitation in November 2024, which is below the monthly average of 1.44 inches. This is also only the second time in the past 15 years in which Jackson received less than an inch of precipitation in both October and November.
Looking at the West as a whole, Wyoming was in an unfortunate drier pocket with above-average precipitation in Colorado and New Mexico, and also across the Far West from California to Washington.
Even though precipitation was below average, believe it or not, snowfall (the amount of snow that fell and accumulated, measured every 24 hours) was actually very close to average.
The town of Jackson received 10.9 inches of snow in November, which is just below the November average of 11.7 inches. The Rendezvous Bowl Plot at Jackson Hole Mountain Resort received 60 inches of snow, which is right around its monthly average.
How could November snowfall be close to average if precipitation was below average?
Some of the higher snowfall events that occurred featured cold air, and snow-to-liquid ratios were higher than normal as a result. Also, nearly all of the precipitation that fell across the lower elevations fell in the form of snow, rather than rain (which can sometimes happen early in the season).
Early December Snowpack Update
While we managed to see some respectable snow events in November, snowpack (the amount of snow on the ground) is well below average heading into December.
This likely has to do with the fact that we received minimal snowfall in October. Typically, we start to build a base over the higher elevations in mid to late October but that did not happen this year.
Also, we have seen dry spells in mid-November and again from late November and into early December, at a time of year when snowpack averages are quickly rising. Low-density snowfall from past storms has settled and compacted into a shallow base during the current dry spell.
The current snow depth at the Rendezvous Bowl Plot at Jackson Hole Mountain Resort is only 20 inches as of December 4, which is only 50% of average. The average snow depth for the date is 40 inches. This is the lowest December 4 snow depth for this location since 1976.
In terms of snow water equivalent (the amount of liquid contained in the snowpack), we are also near historical minimums for early December across the Upper Snake River Basin, which includes the Tetons and Gros Ventres.
For the Western U.S. as a whole, snowpack is near to above average over the Cascades, Sierra, and Southern Rockies, and below average across Wyoming and much of Montana.
December 2024 Outlook:
December is the second coldest month and second snowiest month on average in the Tetons, just slightly behind January. Ski terrain typically opens up quite a bit as the month progresses, though this varies from year to year depending on snowfall.
In the town of Jackson, the average high temperature in December is 29.6ºF and the average low temperature is 8.3ºF. Subzero low temperatures occur in Jackson on an average of 11 days, with -20ºF or lower temperatures occurring in December once out of every three years.
Average December precipitation in Jackson is 1.56 inches and average snowfall is 18.1 inches. The snowiest Decembers in town in recent memory include 34.1 inches in 2016 and 46.2 inches in 2008.
Average December snowfall at the Rendezvous Bowl Plot at Jackson Hole Mountain Resort is 89 inches. The snowiest Decembers on record at this location include 225 inches in 1996, 155 inches in 2016, and 138 inches in 1977.
For December 2024, we are digging ourselves into a hole with a dry start to the month, and it’s tough to say whether or not we will catch up to near average (for the month, and for the season as a whole) by later in the month.
A storm is likely to arrive on Saturday with moderate snowfall possible, but it looks like we will dry out again for at least a few days after this storm. The 7-day snowfall outlook is not totally dry like it was last week, but not overly impressive either.
Heading into mid-December, there are some signs that the pattern could turn more active with the potential for more frequent storms. However, not all models are on board with this and confidence is low as a result.
We’ll see what the second half of the month has in store. Hopefully, the pattern will pick up a bit in time for the holidays but there are no clear signals in the longer-range models yet.
There are some stronger signals in the medium to long-range models for above-normal temperatures overall this month. That doesn’t mean we won’t see some stretches of cold temperatures. Rather, we could see fewer “extreme” cold snaps, and perhaps wetter/denser than normal snowfall in some of our storms compared to a typical December.
Alan Smith, Meteorologist
