US Forest Service Manti-La Sal National Forest

Snow, Weather and Avalanche Advisory

 Introduction:

Good Morning, this is Max Forgensi with the USFS Manti-La Sal Avalanche Center with your with your avalanche and mountain weather advisory for the Wasatch Plateau/Manti Skyline Region, including, but not limited to Ephraim, Huntington and Fairview Canyons. This advisory is brought to you through a partnership of Utah State Parks and the USFS. Today is Sunday, February 27th, 2005 at 7:30 am.

Current Conditions:

Warm temperatures, partly cloudy skies and great riding conditions are expected on the Skyline this weekend! Last weekend’s storm left six inches of powder. The sun has affected the new snow, creating a breakable sun-crust on West through South aspects. On North through East aspects, you will find some nice consolidated powder conditions. There were some cornice failures and at least one new snowmobile triggered avalanche on the Skyline since last weekend, read on to the avalanche conditions for more information. Yesterday, the all the parking lots were packed and the roads were lined, thanks to the road crew for keeping everything in great shape.

Mammoth/Cottonwood SNOTEL (8,800’): 52” of snow on the ground and 8 degrees at 6:00 a.m. High temperature yesterday reached 48 degrees, with a couple of hours during the mid-day that hovered in the low 40’s.

Miller Flat Trailhead: There is 54” of snow on the ground.

Seeley Creek SNOTEL (10,000’): There is 46” of snow on the ground. The 6:00 a.m. temperature is 14 degrees. The high temperature yesterday reached 29 degrees at this SNOTEL stake.

Mountain Weather:

A high-pressure system is over the region currently, the next chance for some snow will be Monday.

Sunday: Partly cloudy. High temperature at 8,000’ will be near 40 degrees.

Sunday night: Partly cloudy. Low temperature at 8,000’ will be 10-15 degrees.

Monday: Mostly cloudy with a 30% chance of snow. High temperatures will be in the upper 30’s.

Avalanche Conditions:

Upon further inspection of the avalanche up North Fork of Lake Canyon, right near the confluence with the South Fork, it was indeed a snowmobile triggered avalanche. It was on a Northeast aspect, started at a 38 degree angle, and its trigger point was a wind load underneath a 15’ cornice. It was 300’ wide, ran for 150’ and was two feet deep. Its terminus was into some trees. An inch square piece of a burnt belt in a small hole was final clue needed to know the trigger. It was probably from the stuck snowmobile trying to gun it out of the debris without adequately clearing the track. Impressive how set up snow can be after it avalanches! If you set off an avalanche, it is important information for the Avalanche Center. Please contact us at (435) 636-3363. The Skyline is a very large area, the more eyes we have the better service we can do for you.

Warm temperatures and lack of any new snow in the past week has allowed the snow to start to settle out and not have any new stress applied to it, besides snowmobiles and skiers. On North through East aspects, the snow is healing, although there is a weakness in the snow pack about 2 feet down which is quite wide-spread. My concern for today on these aspects are trigger points that can transfer the energy of a skier or snowmobiler into this weak layer. Be weary of over-hanging cornices, shallow buried rocks and steep convex rollovers on these aspects. There hasn’t been any “large” avalanches in the past week, what I am concerned about today a possibility of if an avalanche occurs, what the consequences might be; will it push you into a tree? On the other side of the compass, on South and West aspects, expect sun crusts and wet point releases to occur as the day warms up.

The Bottom Line is an avalanche danger of MODERATE on steep slopes greater than 35 degrees where the trigger points mentioned above are present on North through East aspects. For the rest of the Skyline, I am going to rate the avalanche danger at LOW. Remember to practice with your transceivers and always point your snowmobile or skis towards your escape route.