It’s been quite a winter across Teton County. The Rendezvous Bowl Plot at JHMR has broken its all-time snowfall record (pre-ski resort closing day) dating back to 1975.

This has also been the coldest winter in decades across Teton County. Although there are some years with missing data, the snow depth in the Town of Jackson is the deepest on record for this late in the season as of April 5.

Another deep storm cycle in the Tetons from March 29-April 2

A series of storms produced significant snow in the Tetons from last Wednesday through Sunday. Five-day snow totals ranged from 24-37 inches above 8,000 feet during this period while the valley also picked up a few inches.

While conditions have dried out a bit early this week, temperatures have been unseasonably cold, running about 20-25 degrees below average for early April.

On Monday and Tuesday, a powerful storm impacted Central and Eastern Wyoming. In fact, Casper broke its all-time 24-hour snowfall record on Monday with 26.7 inches recorded. This was not just an April record, but an all-time 24-hour record for any month!

Quick March Recap

March was an incredibly cold and snowy month across the region. Temperatures in the Town of Jackson were 9.7ºF below average, making this the coldest March since 1985.

Snowfall was also impressive with 23.5 inches recorded in town – well above the long-term March average of 7.7 inches.

March snowfall in the Tetons was also substantial. Snow totals for the month included 127 inches at Grand Targhee, 117 inches at Jackson Hole’s Rendezvous Bowl Plot, 116 inches at the Raymer Plot and 80 inches at Mid-Mountain.

Cold Temperatures

Snowfall has been one thing, but this winter has also been exceptionally cold across Teton County. Temperatures were below average every month from November to March, and in three of these five months (Nov, Feb, Mar), temperatures were more than 7ºF below average in the Town of Jackson. With the caveat that there are some years with missing data, this was the coldest November-March period in the Town of Jackson since 1961-1962, and the coldest at the Moran/Jackson Lake weather station since 1984-1985!

Season-to-date Snowfall

Based on total snowfall through closing day at the ski resorts (typically the first or second Sunday in April at Jackson Hole), the Rendezvous Bowl Plot at Jackson Hole’s upper mountain has set a new record.

As of April 5, the Rendezvous Bowl Plot has received 590 inches of snow, breaking the old record of 585 inches set in 2016-2017. Records at this location date back to 1975.

 

 

The Raymer Plot, also located at Jackson Hole’s upper mountain, is currently in second place on its all-time list with 565 inches. The record at this location is 605 inches, set in 2007-2008. This record will not be broken since closing day is this Sunday. The 2007-2008 season is also the only time that a snowfall plot at Jackson Hole has cracked the 600-inch mark prior to closing day.

 

 

Snowfall at the Mid-Mountain Plot is not quite as impressive from a historical standpoint and is “only” in eighth place on the all-time list, dating back to 1975.

 

 

Grand Targhee’s Chief Joseph Bowl Plot only has records dating back to 2011. However, during this relatively short 13-year timeframe, this winter has been the snowiest on record with 576 inches, breaking the old record of 574 inches in 2011.

Here is a list of snowfall totals compared to average across Teton County:

 

 

Snowpack Update

The depth of the snow on the ground as of April 1 (the standard date for evaluating snowpack) was not quite at record levels for areas with long-term data, but still very impressive.

Snow depth was at record levels at Grand Targhee and Snow King on April 1, but records at these two locations only date back to 2011.

Snow depth at Jackson Hole’s Rendezvous Bowl Plot was the eighth deepest on record as of April 1 with 134 inches of snow on the ground. Snow depth above 8,000 feet is generally 120-140% of average as of April 1.

 

 

Perhaps most impressive is the snowpack in the lower valley including the Town of Jackson, thanks to heavy mid and late-winter snowfall along with unseasonably cold temperatures in March and early April.

Snow depth in the Town of Jackson was the second deepest on record as of April 1. However, as of April 5, snow depth in town was the deepest on record for the date with 26 inches of snow still on the ground.

Caveat: There are years with missing data in Jackson’s record books (dating back to the early 1900s), so it’s possible there could have been a deeper April 5 snowpack at some point. But regardless, this amount of snow on the ground in town for April is exceptional, and also highly unusual.

Snowpack as evaluated in terms of water content is currently 122% of average in the Upper Snake River Basin, which includes the Teton, Snake River, and Gros Ventre Ranges.

 

 

Snowpack is also very healthy across the state of Wyoming as a whole, and this week’s storm also provided a nice boost across central and eastern portions of the state. While the deep snow is certainly welcome from a drought and water resources standpoint, the risk of stream and river flooding will be higher than usual this spring.

 

 

Finally – A Taste of Spring Ahead

While temperatures remain unseasonably cold on Wednesday, we are going to see our first hints of spring from late this week through early next week. Valley high temperatures will warm up into the upper 30s on Thursday, mid/upper 40s on Friday and Saturday and mid/upper 50s on Sunday and Monday.

While the warmer temperatures will be welcome by many, the downside of our deep late season valley snowpack is that snowmelt is going to accelerate during this warm spell, and some minor flooding will be possible in the valley since the ground has not thawed out yet and will have a tough time absorbing the rapid runoff. Hopefully there won’t be any major issues, but it’s worth keeping an eye on.

In terms of precipitation, a weak disturbance will pass north of our area on Friday night and Saturday, resulting in a chance of light snow showers. But this setup is marginal, so any accumulations will be light and confined to the higher elevations.

Dry conditions will resume on Sunday and likely most of Monday, then a storm approaching from the west will bring a chance of snow showers on Monday night and Tuesday along with a cooling trend by the middle of next week.

Closing day at Jackson Hole Mountain Resort on Sunday should be fun with warm, spring-like conditions.

The jet stream will be located over the Pacific Northwest and Western Canada for most of the next week before dipping further south by around Tuesday of next week.

 

 

Extended Outlook

Our first true taste of spring will be fairly short-lived as a cooler and more active pattern returns during the second half of next week, and likely beyond. Temperatures will fall below average yet again, but it won’t be as cold compared to recent weeks and the valley snowpack will gradually continue to melt off.

The average high in April in Jackson is 54ºF, so below-average at this time of year typically means 40s for highs.

The cool temperatures will prevent much if any melting from occurring across the higher elevations, where an above-average snowpack is likely to persist late into the spring.

Alan Smith, Meteorologist

Alan is a professional meteorologist who holds a degree from MSU Denver and writes weather forecasts for Buckrail. He has lived in Jackson full-time since 2015. He is currently a Meteorologist and Operations Manager for OpenSnow, which is a weather forecasting service for skiing and outdoor adventures. At OpenSnow, Alan writes forecasts for the Tetons, Pacific Northwest, British Columbia, and North America as a whole.