Logan Avalanche Advisory

Forecaster: Toby Weed

SPECIAL ANNOUNCEMENT

The Friends of the Utah Avalanche Center in Logan is offering a Backcountry 101 class next weekend... The class starts with a classroom session on Friday evening, and includes a field day in the backcountry on Saturday. click HERE for more details....


BOTTOM LINE

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


Danger Rose Tutorial

There is a Level 1 or Low danger in the backcountry around Logan, and avalanches are generally unlikely. However, exceptions still exist and wind slab avalanches are possible on some isolated steep drifted slopes, mainly at upper elevations. Generally manageable triggered loose dry sluffs are also likely in steep terrain.. Generally safe avalanche conditions exist in most areas, but you should watch out for loose sugary snow on very steep slopes and unstable stiff wind slabs in exposed upper elevation terrain... It's best to avoid steep slopes with rocks, trees, or other potential terrain traps below that you could be swept into by even a small avalanche....


CURRENT CONDITIONS

The Tony Grove Snotel at 8400' reports 18 degrees this morning, and there is 30 inches of total snow on the ground.. With 6.8 inches of water equivalent, the station sits at 83% of average for the date.. It's 15 degrees at the 9700' CSI Logan Peak weather station, and the station recorded overnight hourly average windspeeds of greater than 20 mph from the west and northwest.

You'll find generally shallow coverage and boney snow conditions in the backcountry.. In many areas that were fairly supportable last week, you now sink deeply down into weak sugary facets.. It is easy to hit rocks in un-compacted terrain when traveling on skis or a sled these days, so you should keep your speed down. The strength of the snowpack is noticeably deteriorating with this clear cold weather, and we are certainly set up for dangerous avalanche conditions when the inevitable snow finally comes....


RECENT ACTIVITY

No new avalanches were reported from the Logan Area, but I noticed evidence of a couple old natural wind slab avalanches near the ridgetop in upper Cottonwood that look to have occurred earlier in the week or last weekend..

We are monitoring the deteriorating shallow snowpack as high pressure conditions and cold air temperatures are causing it to weaken significantly. The shallow snow is subjected to an extreme temperature gradient when the air temperature is cold. A temperature gradient drives sublimation of water vapor through the snowpack, which transforms the snow crystals into weak sugary non-cohesive grains called facets. For sure we need snow, but unfortunately the next significant dump will bring with it a drastic rise in avalanche danger...


THREAT #1

WHERE PROBABILITY SIZE TREND
      Over the next 12 hours.

Most of the several-day-old wind slabs are limp or very stubborn, and the danger will be limited only to very steep slopes. Watch out for stiff wind slabs in exposed very steep terrain. Avoid rounded, chalky looking, or hollow sounding drifts on steep slopes near ridgelines and in and around terrain features.. Generally manageable loose dry sluffs involving weak surface snow are likely on steep slopes today, so avoid terrain where you could be swept into rocks or trees below.. Obviously, the consequence of being caught in an early season avalanche is greatly increased by the shallowly buried and exposed rocks you could be raked over...


MOUNTAIN WEATHER

Expect another sunny and fair day in the mountains today, with a westerly breeze and high temperatures a few degrees warmer than yesterday reaching a high of around 29 degrees. The strong high pressure system overhead and controlling our weather will stay in place through the weekend, but it looks like we're in for a change in the pattern for next week.... It looks like a system moving over southern California will be enough to push the high pressure eastward and bring some snowfall to the central and southern mountains early next week... A bit of snow is possible in northern Utah, depending on the track of this storm... A sizable trough of low pressure and more active weather is expected to move over the region by late next week, and at least some snow is a likely result..


GENERAL ANNOUNCEMENTS

Come support the Friends of the Utah Avalanche Center in Logan next Thursday December 16th at 7:30 pm at the Logan Arthouse and Cinema. We'll be showing KGB's newest film "Wyoming Triumph.' Admission is $10 and tickets can be pre-purchased at http://utahavalanchecenter.org/wyoming_triumph/120611. We'll have a raffle of great gear to support the Friends, so come and get some relief from Finals and enjoy the show! Call 757-2794 for more info.

You have the opportunity to participate in the creation of our own community avalanche advisory by submitting avalanche and snow observations. You can also call us at 435-757-7578 or 801-524-5304 or email by clicking HERE

Donate to your favorite non-profit – The Friends of the Utah Avalanche Center. The UAC depends on contributions from users like you to support our work.

I will update this advisory by around 7:30 in the morning on Mondays, Wednesdays, Fridays, and Saturdays.....

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 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.