Logan Avalanche Advisory

Forecaster: Toby Weed

BOTTOM LINE

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 MODERATE danger in the backcountry, and dangerous avalanche conditions exist on some terrain features. There are lingering pockets with a CONSIDERABLE danger of triggered wind slab avalanches and cornice falls on upper elevation lee slopes steeper than around 35 degrees. Solar warming will cause a rising danger and wet avalanches are possible on steep slopes with saturated fresh surface snow.

Evaluate the snow and terrain carefully and use good travel habits....


CURRENT CONDITIONS

You'll find the best powder conditions today in sheltered mid-elevation terrain. Upper elevation slopes are mostly wind-effected and rimed...

The total snow stake at the Tony Grove Snotel reports 80 inches of snow containing 100% of normal water content for the date. The station reports around 5 inches of added water accumulation in the last week.

It's 17 degrees at 9700', and the Campbell Scientific weather station on Logan Peak is recording 20 mph winds from the north this morning.


RECENT ACTIVITY

There was a fairly extensive natural avalanche cycle last weekend in the region, and I observed evidence of several nice avalanches in the Tony Grove Area ( 1-26-09 photos ) and the Logan Peak Area ( 1-27-09 photos )

Backcountry snowboard riders have been caught and taken for rides in avalanches both yesterday and the day before in the Central Wasatch Range (Wasatch Advisory)


THREAT #1

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

Extensive drifting on Wednesday changed the landscape at upper elevations, and there are now huge drifts and deep, stiff, wind slabs. Yesterday, these appeared well bonded in the Logan Peak Area, but I didn't dare venture into lee terrain where the most accumulation occurred. The drifting snow rebuilt huge existing cornices, which often break further back than you might expect. A cornice dropping onto a drifted slope below might very well trigger a wind slab avalanche. In some cases, wind slabs may pull out on last week's old snow surface, and these have the potential to be large and destructive avalanches.

Avoid obvious drifts on steep slopes, and give the huge freshly built-out cornices wide berth.


THREAT #2

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

The sun will come out for the first time in several days, and loose wet avalanches will become more likely on sunny slopes with saturated surface snow.


MOUNTAIN WEATHER

A dry cold front will affect the region this weekend, bringing a chance for some snow and keeping the inversion at bay for the time being. Expect west winds today shifting around from the southwest and increasing a bit tomorrow. Mountain temperatures will reach the upper thirties today and drop to around 20 degrees tonight.

A strong high pressure system will control next week's weather pattern....


GENERAL ANNOUNCEMENTS

The Friend's of the Utah Avalanche Center and the USU Outdoor Recreation Center will offer another Avalanche Fundamentals (level 1 certification) class on February 5,6,7. Contact the USU ORC at 797-3264 to register or for more information.

Our "Know before You Go" video is available online..... (click HERE to watch it)

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.

I will update this advisory by around 7:30 tomorrow morning.


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.