Wasatch Cache National Forest

In partnership with: The Friends of the Utah Avalanche Forecast Center, Utah Department of Public Safety Division of Comprehensive Emergency Management, Salt Lake County, and Utah State Parks

The FS Utah Avalanche Center’s Home page has moved!

Our new URL is: http://www.avalanche.org/~uac/ please update your Bookmarks!

Avalanche advisory

MOnday, April 1, 2002 07:30 AM

NEW!

If you want this forecast e-mailed to you each day, click here.

If you want to see photos of recent avalanches, click here.

If you want to see photos of avalanche terrain, click here.

If you want recent archives of this advisory, click here.

Good morning, this is Drew Hardesty with the Forest Service Utah Avalanche Center with your backcountry avalanche and mountain weather advisory. Today is Monday, April Fool’s Day, 2002, and it’s 7:30 a.m.

Current Conditions:

Under clear skies overnight temperatures dropped into the low 30’s at most mountain locations, with cold air pooling down into the drainages. The winds have been averaging in the high twenties and thirties out of the west northwest, and should increase to strong by tonight.

There’s a wide array of backcountry snow surface conditions, though most have crusts of varying degrees of supportability. However, if you look hard enough, you can still ride or ski corn and recycled powder on the same day. Melt freeze crusts are supportable on southerly facing slopes below about 9,500’ feet. If you are looking for corn you need to start early and to help you with those alpine starts we will be doing a corn hunters report on the (801) 364-1581 line at 6:00 am for the rest of the season.

Avalanche Conditions:

These corn avalanches are getting to be pretty interesting. Two more were reported from the Canyons backcountry, one from yesterday, and one from the day before. Also from yesterday was another avalanche reported off the south side of Jupiter Peak, which may have been a corn avalanche as well. By and large, all of these were from 4”-2’ deep, with some propagating up to 300’ wide. All were human triggered on mid-elevation sunny aspects, with slope angles in the mid to upper 30’s. What’s clear is that we are still in the early stages of a corn cycle. Here’s the scenario: in the morning, the upper couple inches may be supportable with an overnight refreeze, but the underlying melt-freeze snow is still unfrozen and unsupportable. While the snow mechanics of these unusual things are admittedly a little baffling, they do resemble the classic “slab” over “weak layer” scenario. If you can push your ski pole through a relatively thin melt-freeze crust, or if you hear and feel collapsing in the snow, it might be time to head somewhere else. Here’s a photo of one taken Friday on Reynolds Peak .

Today is going to be the warmest day in our current pattern. Last night’s relatively weak overnight refreeze combined with today’s clear skies and projected 8000’ highs in the mid and upper 50’, the snow surfaces will heat up much faster today. As with most things in life, timing is everything: if you see wet point-release avalanches, roller balls, or are sinking up to your shins in the wet glop, it’s time to change your aspect or set your alarm earlier for tomorrow. Keep in mind that rocky outcrops, cliff-bands, and to some extent trees are notorious for starting points of wet activity.

There are still a couple of other concerns. One, of course, is the lingering deep slab instability – strength tests continue to indicate that our deeply buried weak layers are still sensitive on the northwest through east mid and upper elevation aspects. The other concern is the potential for glide avalanches on the steepest slopes underlain by a rocky slab. Glide cracks have been observed on some of this type of terrain.

Bottom Line:

The avalanche danger remains MODERATE on northwest, north and east facing slopes steeper than about 35 degrees. On southerly facing slopes the danger is generally LOW this morning but will rise to MODERATE with daytime heating. There is also a MODERATE danger of triggering a deep, very dangerous hard slab avalanche in steep terrain, especially in thinner snowpack areas.

(Ogden Area and Western Uinta Mountains)

Same as Salt Lake Mountains.

(Provo Area Mountains)

Same as Salt Lake Mountains.

Mountain Weather:

Under clear skies, today will be even warmer than yesterday, with 8000’ highs in the mid-50’s. 10,000’ temperatures will be in the mid to high 30’s. The winds will be out of the west-northwest, with hourly averages in the upper twenties, increasing to strong tonight. A dry cold front is forecast to move through the Wasatch Mountains tonight, with the temperatures dropping off about 10 degrees. High pressure remains through Friday, with a weak system arriving by Saturday.

General Information:

Wasatch Powderbird Guides will not be flying today. For more information call 521-6040 ext. 5280.

To report backcountry snow and avalanche conditions, especially if you observe or trigger an avalanche, you can leave a message at (801) 524-5304 or 1-800-662-4140. Or you can e-mail an observation to [email protected], or you can fax an observation to 801-524-6301.

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 advisory by 7:30 tomorrow morning.

Thanks for calling!

________________________________________________________________________

For more detailed weather information go to our Mountain Weather Advisory

National Weather Service - Salt Lake City - Snow.

For an explanation of avalanche danger ratings:

http://www.avalanche.org/usdanger.htm