Storm produces heavy snow, strong winds across Teton County

JACKSON, Wyo. – A powerful storm cycle impacted the Tetons from Saturday through Wednesday with deep snow totals adding up across the Tetons and even the lower elevations, while high winds wreaked havoc on travel conditions as well as ski resort operations.

February 18-22 Storm Recap

A multi-day storm cycle impacted Western Wyoming from Saturday through Wednesday with deep snow totals adding up, while an arctic cold front moved through at the end of the cycle on Wednesday.

The active pattern began on Saturday afternoon and Saturday night as a leading-edge disturbance arrived from the northwest. This first wave produced 15 inches of snow at Grand Targhee by Sunday morning, and snow quality was low-density powder withs snow-liquid ratios of 15 to 1 (1″ of liquid = 15″ of snow).

Jackson Hole Mountain Resort received 5-7 inches with this first wave with light accumulations in the valleys.

Light snow during the day on Sunday gave way to heavier snow on Sunday night as a deep trough of low pressure over British Columbia began to work its way southward into the Pacific Northwest and Northern U.S. Rockies.

The Tetons picked up another 5-12 inches of snow on Sunday-Sunday night with light accumulations in the valleys. Milder air and gusty winds also resulted in higher-density snow with snow-liquid ratios of 10 to 1.

Snow continued throughout the day on Monday and winds became very strong out of the west/southwest on across the higher elevation east side of the Tetons with gusts of over 60 mph at the top of the tram at JHMR. This resulted in substantial lift delays at JHMR, while winds were relatively lighter at Grand Targhee.

New snow amounts on Monday-Monday night ranged from 5-10 inches in the Tetons and 2-6 inches in the valleys. Snowfall was fairly dense with snow-liquid ratios ranging from 8:1 to 10:1.

The strongest part of the storm moved through on Tuesday morning with very heavy snowfall rates (in excess of 2″ per hour) both in the Tetons and across the Jackson Hole Valley.

Strong winds also occurred on Tuesday morning in both the mountains and the valley, but the highest gusts occurred in the northern portion of Grand Teton National Park and at Grand Targhee where lift operations were impacted, while JHMR experienced lighter winds compared to Monday.

Snow totals on Tuesday ranged from 7-12 inches in the Tetons while Snow King also picked up 10 inches. The Jackson Hole Valley also received 6-9 inches during the heaviest part of the storm on Tuesday.

On Wednesday morning, an arctic cold front moved through from the northeast, resulting in very strong winds in the Tetons and Jackson Hole Valley with a peak gust of 52 mph reported at the Jackson Hole Airport. Off-and-on snow showers continued during the day on Wednesday as well.

Here are the latest storm snowfall totals from Saturday (Feb 18) through Wednesday morning (Feb 22):

42″ – Grand Targhee Snotel
38″ – Grand Targhee Chief Joseph Bowl
36″ – Jackson Hole Raymer Plot
27″ – Jackson Hole Mid-Mountain
26″ – Jackson Hole Rendezvous Bowl
25″ – Surprise Lake (GTNP)
18″ – Togwotee Pass
17″ – Snow King
16″ – Wilson/Fall Creek Road
12.5″ – Alta
12″ – Jackson Lake/Moran
9.4″ – Jackson
9″ – Jackson Hole Base

Also, here are some of the peak wind gusts that occurred across the region between Monday and Wednesday:

66 mph – Surprise Pinnacle (GTNP)
65 mph – Jackson Hole Summit (top of the tram)
52 mph – Jackson Hole Raymer Plot
52 mph – Jackson Hole Airport
52 mph – Driggs Airport
50 mph – Jackson Hole Buffalo Bowl

Strong winds and blowing snow resulted in numerous road closures across Teton County, Western and Central Wyoming, and Eastern Idaho on Wednesday.

Heavy snowfall rates, varying snow densities and strong winds with variable wind directions have created dangerous and complex avalanche conditions. Be sure to check out the latest Bridger-Teton Avalanche Center forecast before heading into the backcountry.

Snowfall and Snowpack Update

Jackson Hole’s Rendezvous Bowl Plot has now topped 400 inches on the season, which is already above average for the season. The Town of Jackson is nearing its seasonal average for snowfall as well.

Here are the latest monthly and season-to-date snowfall totals across the region.

While snowfall has been healthy this year, snowpack (the amount of snow on the ground) had actually been trending downward relative to average due to a lower frequency of storms during much of January and the first half of February.

After dropping below average briefly, the latest storm cycle has boosted the snowpack to 106% of average for the date across the Upper Snake River Basin.

Snowpack is also above average for almost the entire state of Wyoming.

Snowpack remains well above average across the Sierra Nevada Range, Wasatch Range, Southern Rockies, and Southwest U.S. while snowpack is near average across the Pacific Northwest and Northern Rockies.

Unsettled pattern continues through the end of February

During our last major storm cycle in late January, we headed right back into a dry pattern. That will not be the case this time as we finish out February and head into March.

Arctic air has worked its way into the area on Wednesday and temperatures are much colder as a result compared to prior days during the storm cycle, which were actually quite mild.

However, the bottom will not completely drop out during this arctic spell thanks to a trough of low pressure developing off the West Coast which will place us under a southwest flow from Wednesday night through Friday night. This will result in several pulses of moisture arriving with snow showers likely.

The southwest winds will also help to moderate temperatures somewhat – it will still be cold with highs in the teens to 20s in the valley and single digits to teens in the mountains. But overnight temperatures will not drop as low as they could.

A general 1-3 inches of snow can be expected in the Tetons on Wednesday night and again on Thursday-Thursday night, and a dusting to 2 inches can be expected on Friday. Valley snow amounts will generally be less than an inch each day. While snow amounts will be on the lighter side, snow quality will be drier and more powdery with cold air in place.

On Saturday, we will see a break in the pattern with warmer temperatures and highs in the 20s in the mountains and 30s in the valleys.

The break will be short-lived as two storms are projected to reach the Tetons around Sunday-Monday and again next Tuesday-Wednesday (February 28-March 1).

Here is a seven-day snowfall projection from multiple simulations of the European weather model, which indicates more snow is likely for the Tetons, while the Western U.S. as a whole looks will remain in a snowy pattern.

Extended Outlook

If you’re hoping for some early signs of spring heading into the month of March, you are going to be disappointed. An active pattern is likely to continue across the Tetons and Western U.S. as a whole through at least the first week of March with relatively frequent snow chances expected along with consistently below average temperatures.

Alan Smith, Meteorologist