Recent Snowfall:

Saturday's quick-hitting storm was a continuation of a recent trend of weak storms over-performing, and that is never a bad thing! 

On Sunday morning, JHMR is reporting 4 inches of new snow at its upper mountain plots, 3 inches at mid-mountain, and 2 inches at the base. Snow King is also reporting 2 inches.

Grand Targhee was the big winner, however, and is reporting 8 inches of new snow on Sunday morning. This was an example of "Targhee magic" in which moisture was being lifted by the terrain up the western side of the Tetons – something that is not always picked up well by the models when other storm "features" are lacking.

Forecast for Sunday - Monday:

We are already seeing some moisture arriving ahead of our next storm, resulting in light snow showers on Sunday morning. Periods of off-and-on snow showers will continue throughout the daytime hours on Sunday, perhaps picking up a bit on Sunday afternoon.

Skies will remain mostly cloudy throughout the day and winds will also pick up as the day progresses.

Snowfall will become heavier and more widespread by Sunday evening as the storm approaches. Heavy snow can be expected throughout the overnight hours on Sunday night with 1-3"/hour snowfall rates possible at times above 8,000 feet.

West/southwest winds will also gust to 60+ mph overnight near the summits of JHMR and Targhee.

On Monday morning, snowfall will become more intermittent with some lulls occurring early in the day. However, lingering moisture and a strong westerly flow will continue across the area throughout the day on Monday, and the atmosphere will also become unstable as colder air arrives in the middle to upper atmosphere.

This instability will result in snow showers re-developing throughout the day and into the evening, resulting in locally heavy snowfall rates at times. Snow showers should eventually taper off to scattered flurries after midnight on Monday night.

Westerly winds will be gusty throughout the day on Monday, though not quite as strong compared to Sunday night.

Snow Totals:

I'm upping my storm total forecast slightly to 12-22 inches for the Tetons above 8,000 feet through Monday night. Breaking it down by day, we should see 8-14 inches on Sunday-Sunday night, and 4-8 inches on Monday-Monday night.

Monday will offer the deepest conditions on the slopes, and the snow quality will be outstanding with high snow-liquid ratios. Just keep in mind that it's still early in the season with thin coverage and the amount of terrain open at the resorts is limited. 

For the Jackson Hole Valley and Snow King, I'm expecting storm total snowfall to range from 4-8 inches through Monday night. Further east, Togwotee Pass should pick up 7-14 inches. 

Teton Pass Travel Conditions:

Winter driving conditions can be expected over the pass and on some of the valley roads during the day on Sunday, but overall conditions will be relatively favorable ahead of the strongest part of the storm.

Travel conditions will quickly deteriorate on Sunday evening and into Monday morning with heavy snowfall rates, blowing snow, and limited visibility expected over the pass and in the valley. Difficult travel will likely persist into Monday afternoon/evening with locally heavy snowfall rates and significant blowing snow.

Improvement is expected on Tuesday once the storm has exited the area.

Forecast for Tuesday - Wednesday:

The big storm will be over by Tuesday, but a secondary weak disturbance is expected to arrive from the west, resulting in additional light snow showers and flurries developing between Tuesday morning and Tuesday evening.

The Tetons could pick up another 1-2 inches of low density powder with a trace to a half-inch in the valley. Otherwise, it will be a very cold day as arctic air settles into place behind Monday's storm, with highs only reaching the low teens in the valley and hovering around zero on the upper slopes of JHMR and Targhee.

Wednesday is trending drier and also warmer as high pressure builds in from the south briefly, shifting the main storm track to the west and north. Highs will warm up into the teens on the upper mountain. The valley is a question mark in terms of temperatures, depending on whether or not an inversion sets up, or if southwest winds are strong enough to keep the atmosphere "well mixed" to prevent an inversion.

An active pattern is likely to resume late this week and into early next week, though models are in poor agreement regarding the timing and details of each storm system.

For now, it looks like the first storm will arrive from the southwest in the Thursday (12/1) to Friday (12/2) timeframe, with another storm possible in the Saturday (12/3) to Monday (12/5) timeframe.

It's way too early to get into the details given the poor model consistency, but it's likely we will pick up more snow between December 1st and 5th, and it's possible we could see heavy snow at some point. 

From December 5th-11th, the storm door is projected to remain open with additional shots of snow possible, and there is good agreement among the major long-range models that temperatures will continue to run colder than average. 

Thanks so much for reading! Next update on Monday (11/28).

ALAN SMITH