Logan Avalanche Advisory

Forecaster: Toby Weed


We've continued a Special Avalanche Advisory through the evening Monday, February 15th. Recent new snow over the last few days has covered up some very weak snow formed earlier in the week which has produced widespread avalanche activity. This weakness is expected to be active again today with human triggered avalanches likely on slopes approaching 30 degrees and steeper.


Danger by aspect and elevation on slopes approaching 35° or steeper.
(click HERE for tomorrow's danger rating)

Danger Rose Tutorial

Overall, there's a CONSIDERABLE (3) danger in the backcountry. Some natural avalanches are possible today with snowfall, mild temperatures, and westerly winds forecast, and easily triggered avalanches 1 to 3 feet deep are likely on slopes steeper than about 30 degrees. There are pockets with a HIGH (4) danger on steep upper elevation slopes with significant deposits of recently accumulated or wind drifted snow. In some areas, where weak snow still plagues the basal layers of the snowpack, you could trigger a very dangerous deep slab avalanche. The next "our worst nightmare" kind of avalanche will most likely be triggered from a generally shallow area. A smaller avalanche overrunning a slope with weak snow structure could cause a much larger and more destructive avalanche... You could trigger avalanches remotely, from a good distance, or from below.....

Careful snowpack evaluation, cautious route-finding and conservative decision-making are essential for safe backcountry travel today. Avoid travel on or under steep slopes and obvious or historic avalanche paths.


Its snowing in the mountains this morning. The Tony Grove Snotel at 8400' already reports a couple inches of new snow and now over 2.5 inches of water capping an active surface hoar or frost layer formed earlier in the week and preserved by light density snowfall on Wednesday. There's now 76" of total snow on the ground containing 70% of average water for the date. Its a balmy 21 degrees at the 9700' Campbell Scientific--Logan Peak weather station, and the wind is out of the west, averaging around 12 mph.


We've had a very active weekend locally with numerous natural and easily or remote triggered avalanches reported across the forecast zone....By far the vast majority of these avalanches involved the newest layer of snow picked up since a nice layer of surface hoar was covered and preserved by light snow on Wednesday 2-10-10.

Here's an updated local backcountry avalanche list:


      Over the next 24 hours.

Surface hoar or frost was observed earlier in the week from the valley floors to the highest ridgetops across the region.....We've observed easily and remotely triggered and natural avalanches stepping down to this persistent buried layer, and some of these are occurring on fairly low angle slopes... With today's additional new snow and west winds, more natural avalanches are possible today. I'd expect triggered avalanches if folks venture onto slopes with significant deposits of new or especially drifted snow.....

Watch for and avoid fresh drifts on the lee side of exposed ridges and in and around terrain features like gullies or sub-ridges. Keep in mind that the weight of a smaller avalanche overrunning a slope with a poor snow structure could cause a much larger and more dangerous avalanche.


      Over the next 24 hours.

The now deeply buried weak sugary or faceted snow is notoriously slow to heal, and recent natural deep slab activity in the area proves that this dragon is still hanging around .. Very dangerous, triggered deep slab avalanches are probable if people venture into in steep terrain that didn't recently avalanche. Deep slab avalanches can most easily be initiated from a shallower area on the slab, so watch out for steep rocky or terrain with generally shallow snow cover. In some areas, you still might trigger a dangerous avalanche from a distance or from below. Triggered deep slab avalanches will step down to weak snow near the ground and be very broad and destructive.


Winds are moderate out of the west this morning and it is snowing in the mountains...Mountain temperatures should stay fairly constant in the mid twenties today. Expect a break in the the somewhat moist northwest flow and fairer weather tomorrow before the next wave of storminess around Wednesday night.


I will be issuing morning avalanche advisories for the Logan area on Mondays, Wednesdays, Fridays and Saturdays.

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Send us your avalanche and snow observations. You can also call me at 435-757-7578 or the SLC office at 800-662-4140, or email to uac@utahavalanchecenter.org

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The information in this advisory is from the U.S. Forest Service, which is solely responsible for its content. This advisory describes general avalanche conditions and local variations always occur.

I will update this forecast Wednesday morning. Thanks for checking in....

This information does not apply to developed ski areas or highways where avalanche control is normally done.  This advisory is from the U.S.D.A. Forest Service, which is solely responsible for its content. This advisory describes general avalanche conditions and local variations always occur.

This advisory provided by the USDA Forest Service, in partnership with:

The Friends of the Utah Avalanche Center, Utah Division of State Parks and Recreation, Utah Division of Emergency Management, Salt Lake County, Salt Lake Unified Fire Authority and the friends of the La Sal Avalanche Center. See our Sponsors Page for a complete list.