Forecast for the Logan Area Mountains

Toby Weed
Issued by Toby Weed for
Monday, December 24, 2012

Heavy snowfall will create a rising avalanche danger in the backcountry today. The danger will rise to CONSIDERABLE (or level 3), and storm snow and soft wind slab avalanches will become probable, especially during periods of intense or very heavy snowfall. Natural avalanches are possible, so avoid travel beneath steep slopes and avalanche run-out zones. You also might trigger dangerous persistent slab avalanches on steep previously drifted slopes, most likely on upper elevation slopes facing the northern half of the compass and in areas with generally shallow and weak underlying old snow. Avalanches in some areas might be triggered remotely from a distance or below. Evaluate the snow and terrain carefully, and continue to make conservative decisions regarding your route selection.

Low
Moderate
Considerable
High
Extreme
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Weather and Snow

Don't forget the extra goggles. You'll find nice fresh powder today in the mountains, with a storm total of around a foot likely around 8000'. The Tony Grove Snotel reports 5 inches of new snow and 7/10ths of an inch of water overnight. There's 52 inches of total snow, 97% of average water content for the date, and it's 24 degrees at 8400' this morning. Campbell Scientific's 9700' Logan Peak weather station reports a current temperature of 18 degrees, and the winds this morning shifted around from the west and diminished after being sustained and strong from the south for the past few days. West winds are currently averaging 10 to 15 mph at the mountain top level...

Recent Avalanches

We've observed evidence of widespread natural avalanche activity from Monday's intense storm across the Logan Zone on upper elevation slopes facing northwest through east. There were also a couple smallish natural and triggered wind slab avalanches in the zone late last week at upper elevations and on slopes facing north and northeast.

Ad
Avalanche Problem #1
New Snow
Type
Location
Likelihood
Size
Description

Storm snow and fresh wind slab avalanches will become likely today, especially during periods of intense or very heavy snowfall. Natural avalanches are possible in steep terrain, so you should avoid travel below steep slopes or in avalanche run-out zones... The fresh snow may not stick so well to the weak sugary snow surface from last week. A layer consisting of small grained near surface facets formed on the surface in many areas during last week's high pressure conditions. Two dimensional frost or surface hoar was also reported, mainly from mid-elevation terrain. Triggered avalanches will become probable on slopes that pick up significant accumulations of new snow, a foot or more. Northwest winds will easily build soft and sensitive wind slabs in exposed terrain...

Avalanche Problem #2
New Snow
Type
Location
Likelihood
Size
Description

There are areas with poor snow structure where you might trigger dangerous and broad slab avalanches releasing on buried persistent weak layers. Stiff wind slabs formed in the past couple days from sustained south winds at upper elevations. In some cases, these slabs built on weak sugary surface snow called near surface facets. Areas with shallow, weak, preexisting snow that are also drifted-in by the recent south winds are the most suspect. Hard slab avalanches running on persistent weak layers in some areas might be triggered remotely from a distance or worse, from below. Pay close attention to red flags like audible collapsing and cracking, and always be willing to reevaluate or turn back.

Additional Information

Expect periods of heavy snow today with storm totals of over a foot likely in some favored upper elevation areas. Temperatures will drop into the mid-teens and we'll see northwest winds averaging in the upper teens. A couple more inches may accumulate tonight, and temperatures will drop into the single digits. We may see a bit of sun on Christmas Day, and it'll be cold, with high temperatures in the teens and a north-northwest breeze. The next Pacific storm will affect mainly northern Utah on Wednesday and Wednesday night, with a pretty good shot of snow quite possible for the mountains around Logan.

Check out the Logan Mountain Weather page...

General Announcements

The friends of the Utah Avalanche Center in Logan is presenting an Advanced Skills backcountry 201 class in early January. A classroom session on the evening of January 3 and a field day on Saturday January 5. Here's a link for more information and registration; Advanced Skills, backcountry 201 or call 435-757-2794.

Discount lift tickets are in and it would be a good day for lift serviced riding! Go to http://www.backcountry.com/utah-avalanche-center to get tickets from our partners at Alta, Beaver Mountain, Brighton, Canyons, Deer Valley, Park City, Powder Mountain, Snowbasin, Snowbird, Solitude, Sundance, and Wolf Mountain. All proceeds benefit the Utah Avalanche Center.

The Friends of the Utah Avalanche Center in Logan have a two person pass for a day of powder skiing or riding with Park City Powder Cats, and they're opening this weekend. If you are interested in a good deal for a memorable powder experience call Paige at 435-757-2794....

Remember your information can save lives. If you see or trigger an avalanche in the backcountry or see anything else we should know about, please participate in the creation of our own community avalanche advisory by submitting snow and avalanche observations. You can also call us at 801-524-5304 or email by clicking HERE. In the Logan Area you can contact Toby Weed directly at 435-757-7578.

This advisory is produced by the U.S.D.A. Forest Service, which is solely responsible for its content. It describes only general avalanche conditions and local variations always exist.