Mountain Weather Summary

11.22.2019

Bottom Line:
Expect generally safe avalanche conditions prior to Thanksgiving week. Storms are forecast to impact the forecast area between Tuesday and Thanksgiving Day. Wind and new snow will combine to quickly increase the likelihood of natural and human-triggered avalanches. Don’t expect the new snow to bond well to the generally weak underlying snow surface. Cracks shooting from your boards or feet are a sure sign you’ve found a sensitive slab.

We will update this post on or before Friday, November 29th, 2019.

Forecast Discussion:
All eyes should be squarely focused on the storm expected to impact the forecast area between Tuesday and Thanksgiving Day. We’ve been lulled to sleep by an extended period of high-pressure. Now it’s time to snap back awake as the possibility of substantial new snow and wind could quickly increase the chances for both natural and human-triggered avalanches.

Thankfully, this early in the season the equation will be relatively simple. New snow falling on dirt and rocks is not an issue. But any slope that held enough snow to cover rocks and logs prior to the Thanksgiving storm will be suspect.

On Wednesday, Ben and I visited the Upper Titus weather station near Galena Pass. The snow cover was highly variable, with dirt on sunnier slopes and up to 16” of weak, faceted snow on shaded aspects. A crust layer near the snow surface, topped with a dusting of new snow and feathery surface hoar provides a concerning base for our next storm. Check out this video for a peek into our trip. Add a healthy dose of new snow and wind to the mix and the generally weak, faceted snow surface is not likely to bond well with any freshly formed wind slab.

There’s a notable difference in current snow cover distribution across the forecast area. The Sawtooth and Western Smoky Mountains boast the deepest snow and best coverage. As you move toward Galena Pass and south toward the Pioneer Mountains, there are more bare slopes and shallower snow depths. Ben recently visited the Red Fish Lake Creek drainage of the Sawtooth Mountains, (photo, photo) reporting a foot of snow on southerly slopes above about 8,000’ and 2-3’ of snow on shadier slopes at similar elevations. Read his full observation here.

Whether you’re an eager skier, hunter, or a peak bagger be on the lookout for areas with obvious signs of wind-drifted snow. If mother nature delivers, expect these fresh drifts to be sensitive to your weight. Even small slides can have big consequences if they knock you off your feet and drag you through trees or over cliffs.

Early-season snow conditions exist in the majority of the forecast area - be alert to stumps and rocks that lurk just below the snow surface. If you do head out, share your photos! Tracking early season snow distribution will help you (and us) anticipate potential problem areas as the winter progresses.

Mountain Weather:
It’s happening, it’s really happening! The pesky high-pressure that’s pushed our beloved snow to the north is finally weakening. Long-range models predict that a well organized low-pressure system will impact the forecast area between Tuesday and Thanksgiving. Currently, I have low confidence in how far this system will dive to the south before crossing our area. Slight changes in its position can make a big difference in snow totals. The latest forecasts suggest that the position of the low will be further to our south, which could favor our southern mountains and valleys. Either way, I’d count on a snowy Thanksgiving.

Today and tomorrow, expect mountain daytime high temperatures in the low 30s F and overnight lows to dip into the low 20s F. On Sunday, a switch to northwest flow and the passage of a weak cold front, will bring both high and low temperatures down by about 10 degrees across the board. Cooler temps will prevail through Thanksgiving before rebounding to near-normal next weekend.

Don’t forget to follow along with this season’s storm-by-storm snow totals by checking our Storm Totals page daily.

Events:
The week after Thanksgiving is chock-full of movie premieres, film festivals, and avalanche education opportunities from multiple providers across the state. Check our Education and Events Calendar for details.