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


7:30, Friday April 4, 2008

Hello and good morning, this is Toby Weed of the Utah Avalanche Center with your Logan Area backcountry avalanche and mountain weather advisory.  It’s Friday April 4th, at 7:30 in the morning.  Today’s advisory is brought to you in part by the Friends of the Utah Avalanche Center in Logan with help from Backcountry Access.  

Current Conditions:

There’s still a bit of nice spring powdery snow on upper elevation north facing slopes in the backcountry, but heating from the intense high-angle spring sun melted the fresh surface snow down into slush on most other slopes.  Crusts formed on the snow surface with last night’s freeze, but significantly warmer temperatures today will soften these quite quickly and you’ll find a few inches of saturated mush in most areas.   It is currently 19 degrees at the CSI weather station at 9400’ on Logan Peak with a consistent wind gradually shifting from northwest to west and averaging in the twenties.

Even though you can ride anywhere these days, you should be sure to keep motor vehicles in terrain that’s open.  Riding on public lands designated as “closed to motor vehicles” or as a National Forest Wilderness only jeopardizes the future of your sport, and fines for MV trespass have been recently increased.  (MV wilderness trespass photos)  

  Avalanche Conditions: 

It was active yesterday, with several triggered slab and loose wet avalanches reported in the backcountry of Northern Utah.  At least two people were caught and carried by avalanches in steep terrain in the Central Wasatch and one of these was injured while escaping to the flank of the avalanche into rocks. (Wasatch Bulletin).  Locally, an observer reports triggering a few fairly long-running wet avalanches in the Rattlesnake Canyon Area in the Wellsville Mountain Wilderness.  Natural wet avalanches have been fairly common on steep sunny slopes in the heat of the last couple days (photos).  We noticed evidence of a few natural wind slab avalanches at upper elevations from Monday, (photos) and yesterday afternoon I was still able to kick good sized chunks off of small cornices.  

Wet avalanches will become probable on steep slopes as warmth from intense spring sunshine turns the fresh surface snow into slush.    Exactly when particular slopes will become active is hard to predict, but this time of year solar warming is very intense and when the surface snow becomes saturated it is prone to avalanching.  You might find even smallish wet avalanches entraining lots of mass and traveling far.

The huge cornices in the region now present an obvious danger, especially when it’s windy or warm.  Large cornices may well still be sensitive to your weight today and may break further back than you expect.   It is always a good idea in the spring to stay out from under these monsters, (photos from 3-29).  Triggered wind slab avalanches are still possible on steep upper elevation slopes with significant deposits of recently drifted snow.  Drifts should be fairly obvious, and you should avoid them on steep slopes.


Bottom Line: 

  There’s a MODERATE avalanche danger on slopes steeper than about 35 degrees in the backcountry.  Warmth from the intense spring sun may cause the danger to rise to CONSIDERABLE in some areas, and you are likely to trigger significant wet avalanches on steep slopes with moist or heat-softened surface snow.  Avoid and stay out from under large cornices and steep slopes with saturated snow.

Mountain Weather: Should be mostly clear and warm today ahead of a cold front which will move through the region later tonight.  It’ll be several degrees warmer in the mountains than yesterday, but tonight’s storm will cool things down in time for the weekend.  We could pick up two or three inches of snow overnight and a bit more is possible this weekend, with a series of small storms continuing into next week.

General Announcements: 

Check out the images page for photos of some of this season’s avalanches.

Go to the Avalanche Encyclopedia if you have any questions about terms I use in the advisory.

I'm very interested to know what you're seeing out there.  Please e-mail observations to me at [email protected] or leave me a message at 755-3638, especially if you see or trigger an avalanche in the backcountry. We keep all observations confidential.

This advisory will expire in 24 hours from the posting time.

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.