Wasatch-Cache National Forest  In partnership with:  Utah State Parks and Recreation, Friends of the Utah Avalanche Center-Logan, and Utah State University College of Natural Resources.

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Logan area Avalanche advisory

 December 10, 2006

Hello and good morning, this is Toby Weed of the Utah Avalanche Center in Logan with your backcountry avalanche and mountain weather advisory.  It's Sunday December 10th, and it's 7:00 in the morning.  This advisory is brought to you in part by the Friends of the Utah Avalanche Center in Logan with the help of Import Auto at 502 W, 1400 N. 

Mountain Weather:

This morning the National Weather Service issued a Snow Advisory for most Utah mountains.  The advisory is from 9:00 this morning until 9:00 tomorrow, and the mountains around Logan should receive a decent shot of snow.  Snowfall will intensify during the day today, accompanied by moderate southerly winds.  The cold front will arrive this evening, with lightning possible.  The winds will shift around from the west and then northwest, and snowfall will continue through tonight.  Accumulations could add up to a foot or more in favored upper elevation terrain, with 2 to 4 inches forecast for the Bear River Valley.  More storminess is in store for the upcoming week, with the next wave coming through on Tuesday.

Current Conditions:

It's 22 degrees and the wind is from the south, holding at around 25 mph this morning at the Campbell Scientific weather station on Logan Peak.  Clouds will quickly build up this morning, and snowfall will begin by the time most of us make it up to the trailhead this morning.  After more than a week without any snow, there's a wide variety of surface snow conditions in the backcountry.  You'll find sun crusts of varying strengths on slopes exposed to direct sun,  wind crusts on exposed upper elevation slopes, and rotten feeling sugary snow to the ground on mid-elevation shady slopes or in shallow upper elevation areas.  The snow in many areas is punchy, especially around rocks, and sometimes you sink to your knees in nasty sugary snow.  This can make hill-climbing and turning in un-compacted terrain somewhat hazardous.  Today you should prepare for rapidly accumulating snow.  If you drive up the Tony Grove Road, be aware that road conditions may drastically deteriorate by this evening.

 Avalanche Conditions:

 As snow begins to accumulate on our wide variety of potential weak layers, the avalanche danger will be on the rise. Avalanches remain generally unlikely throughout the region this morning, but by afternoon you might trigger soft slab avalanches on steep slopes.  This afternoon I'd be increasingly cautious on steep slopes with developing drifts or substantial deposits of fresh snow, which may not bond well to the underlying old snow surface.  With a southerly wind in store for today, drifts are likely to form on the very slopes where weak surface snow exists.  In places, drifts are likely to build up on a layer of well developed frost crystals (or surface hoar) or on small sugary grains we call near surface facets. I expect the most danger on upper elevation slopes facing the northern half of the compass. Sunnier slopes sport slick sun crusts of varying strength, which may become sliding surfaces for the accumulating new snow.  In short, I expect things to get interesting and the avalanche danger to increase significantly as snow begins to stack up this week in the backcountry.  

  Bottom Line:

The avalanche danger will rise to MODERATE this afternoon in the backcountry. Triggered soft slab avalanches will become possible on slopes steeper than about 35 degrees as snow piles up during the day.  You're most likely to encounter avalanches later today on exposed upper elevation slopes facing the northern half of the compass. Continued snowfall tonight, especially if  accompanied by strong winds, will cause the danger in the backcountry to rise further by Monday.

General Information:

I'll give a free Avalanche Awareness Talk, open to everyone, at the Logan Ranger District offices on Thursday, December 14th at 6:30.

 The Tony Grove Road is not maintained in the winter.  That means, you can't quite drive a wheeled vehicle all the way to the lake, and you should be prepared to get stuck in a couple feet of snow if you try.  Turning around may be difficult.   With limited access to upper elevation snow elsewhere, there's lots of snow-hungry people on the Tony Grove Road.   Motorized users need to be aware of this, and we need to keep our speed way down in the proximity of pedestrians.   

   I'll update my advisories on Tuesday and Thursday evenings and weekend mornings by about 7:00.  This advisory will expire early Monday morning, and I may issue a special update if the storm warrants.  Normally, I'd update this advisory again on Tuesday evening.  Logan Area advisories will be accessible through the new statewide toll-free avalanche info line; 1-888-999-4019.

If you're confused by some of our avalanche terms check out the cool new Avalanche Encyclopedia.  Please  send backcountry observations to uaclogan@avalanche.org or leave us a message at 755-3638, especially if you see or trigger an avalanche in the backcountry.

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.