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Forecast for the Logan Area Mountains

Toby Weed
Issued by Toby Weed on
Friday morning, February 1, 2013

Dangerous avalanche conditions exist, and there is a CONSIDERABLE (or level 3) avalanche danger in the backcountry. Dangerous triggered persistent slab avalanches are likely in some areas at mid and upper elevations, and wind slab avalanches are still probable on steep drifted slopes. You also might trigger loose wet avalanches on steep lower elevation slopes with saturated snow. Careful snowpack evaluation, cautious route-finding, and conservative decision making will be essential in the backcountry today.

Low
Moderate
Considerable
High
Extreme
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Weather and Snow

The Tony Grove Snotel at 8400' reported about a foot-and-half of new snow since Monday, containing 2-and-a-half inches of water. It's 25 degrees, there is 61 inches of total snow, and 71% of average water content for the date. It's also 25 degrees at the UDOT Hwy 89 weather station, with recorded hourly average wind speeds around 10 mph from the northwest. Wednesday's strong and sustained westerly winds, warm temperatures, heavy inverted fresh snow, and riming played havoc with conditions, but you'll still be able to find decent somewhat heavy powder conditions, especially in more sheltered areas. History tells us that avalanche accidents are likely over the coming weekend. Nice pleasant weather after a very stormy week, and only gradual stabilization of the snowpack with tricky avalanche conditions, and existing persistent weak layers. Heads up people, now is the time to be on top of your game. Tone down your aspirations, be willing to turn around, and make conservative decisions regarding the terrain you plan to ride...

Recent Avalanches

Locally; A side-hilling rider triggered a 200' wide avalanche south of Tony Grove Lake a week ago, and wasn't caught. There was widespread natural storm snow activity across the region on Tuesday, and I've observed evidence indicating that some of the big avalanche paths in the Wellsville Range and Wood Camp Hollow ran naturally then as well. For good reason, few people have been out in the backcountry in the last few days, and I haven't received reports of any recent human triggered avalanches.

Here's a link to our updated avalanche list...

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

Avalanches will likely fail 1 to 3 feet deep on very weak faceted snow created during the drawn-out January high pressure systems. Areas plagued by the shallowly buried January 8 rime-crust , which is intact and fairly widespread in the region, and weak faceted snow associated with it are most suspect. The preexisting snow on shady mid elevation slopes is especially weak, and avalanches could occur in unexpected areas on slopes approaching or steeper than 35 degrees. In these conditions, you could trigger avalanches remotely, from a distance or worse, from below. Recent avalanches, audible collapsing, and cracking are red flags indicating instability...

Avalanche Problem #2
Persistent Weak Layer
Type
Location
Likelihood
Size
Description

I expect that most of the large drifts from the very windy Wednesday will be stubborn or fairly stable by today, but triggered wind slab avalanches are still possible on drifted upper and mid elevation slopes.. Also, significant loading from the drifting will create a higher danger of persistent slab avalanches in areas with buried weak layers. Watch for and avoid stiffer wind slabs on the lee side of major ridges and in and around terrain features like cliff bands, sub-ridges, gullies, and scoops. Potential wind slabs are drifts that often appear smooth or rounded and chalky looking, and they sometimes sound rather hollow. Stiff wind slabs might allow you to get well out on them before releasing.

Avalanche Problem #3
Wet Snow
Type
Location
Likelihood
Size
Description

Loose wet avalanches are possible at lower elevations, especially if the sun comes out for a while and midday temperatures climb above freezing.... Avoid and stay out from under slopes with saturated fresh snow. Roller balls, pin-wheels, and point-release sluffs are all signs that wet avalanche activity is possible.

Additional Information

There is a slight chance for a bit more snow this morning, and it will be mostly cloudy... Expect clearing this afternoon, and we might see a bit of sunshine in the mountains, with temperatures climbing into the upper twenties and a moderate wind from the northwest. High pressure conditions are expected to return to the region late today, and will set up over the area for the weekend, continuing through at least the first half of next week. I'm sorry to say that the high pressure conditions will cause the dreaded inversion to set in, with smog building up in the valleys again. Expect fair weather in the mountains.

Check out the new Logan Mountain Weather page...

General Announcements

The infamous annual CROWBAR backcountry ski race is scheduled for Saturday, February 23 in Beaver Creek Canyon. Click HERE for more details...

For a printer friendly version of this advisory click HERE

Remember your information from the backcountry can save lives. If you see or trigger an avalanche, or see anything else we should know about, please send us your 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.

I will update this advisory on Monday, Wednesday, Friday, and Saturday mornings by around 7:30...

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.