With heavy snowfall and strong winds, the avalanche danger will quickly rise today. Across upper elevation terrain, you will find a CONSIDERABLE avalanche danger for wind-drifted snow avalanches. On slopes facing northwest, north, northeast, and east at the mid and upper elevations, avalanches can break deeper in the snowpack failing on a persistent weak layer. Out of the wind you'll find a MODERATE avalanche danger for new snow avalanches. Depending on how fast the storm snow accumulates, the avalanche danger could rise to CONSIDERABLE on all aspects and elevations.
Strong wind from the past 24 hours has created stiff hard slabs of windblown snow. Today heavy snowfall and strong wind will create new soft slabs of wind-drifted snow. Be on the lookout for and avoid areas that are wind-loaded. These drifts will continue to build throughout the day and become more dangerous as the storm snow stacks up.
Trend: Increasing danger
This avalanche problem will depend on how the new storm snow stacks up. I would imagine that once we see about 6 inches of new snow, we could see soft slab avalanches and sluffing within the new snow. The new snow will fail within the storm snow (density changes) or break down to the old snow surface.
As it snows, continuously check how the new snow is behaving. Use shovel tilt tests and test slopes to see if the new snow is reactive. Remember that the rate at which the snow falls can quickly increase the avalanche danger.
Trend: Increasing danger
Yesterday, I went to Days Draw to check out a slope that had previously avalanched to see if there was any faceted snow. Unfortunately, I found a poor snowpack structure with two prominent layers. One is a dust layer that has some small-grained faceted snow around it. We've seen avalanches from the past week fail on this layer.
The other layer was large-grained faceted snow at the bottom of the snowpack. In any case we are now adding additional weight to the snowpack and these layers could become reactive once again. These avalanches are large enough to catch, carry, and bury humans.
Trend: Increasing danger
A few people sent in pictures of avalanches that happened over the past week. One observer sent in a great observation from White Pine showing recent avalanches caused by wind-drifting and blowing snow (picture below). Check out all avalanches and observations HERE.
Well it's snowing. Weather stations are showing the first snow flakes hitting the boards. The National Weather Service has issued a winter storm warning. Strong wind from the south picked up yesterday and continues to blow 10-25 mph with gusts into the 30s and 40s across the upper elevation ridgelines. Temperatures range from 20-30 °F.
Today, heavy snowfall and strong winds are expected as a storm enters northern Utah. Strong southerly wind will continue to blow 20-30 mph with gusts into the 30s and 40s throughout the day. The wind is expected to switch to the northwest late this afternoon and evening as the cold front pushes through. At that time, we will see the heaviest snowfall, and we could see snowfall rates of 2 inches per hour. By the dinner hour we could see 3-14 inches of new snow with 0.25 - 1.20 inches of water. All said and done, this storm could bring 1-3 feet of new snow.
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This information does not apply to developed ski areas or highways where avalanche control is normally done. This forecast is from the U.S.D.A. Forest Service, which is solely responsible for its content. This forecast describes general avalanche conditions and local variations always occur.
