Manti-La Sal Avalanche Center

US Forest Service Manti-La Sal National Forest

Introduction:

Good Morning! This is Evan Stevens with the USFS Manti-La Sal Avalanche Center with your avalanche and mountain weather advisory. Today is Saturday, December 13th, 2003 at 7:30 A.M

General Conditions:

Overcast skies this morning with a temperature of 25 in town and 17 at the Geyser Pass Trailhead. Some great settled powder still exists at and below treeline making for some excellent skiing, riding and snowmobiling. Above treeline look for some shallow wind drifts and wind affected snow, making conditions a little punchier in the exposed locations. The road is plowed, snowpacked and slick, so drive slow, and 4WD may come in handy.

Mountain Weather:

A beautiful day is on tap, with partly cloudy skies and temps in the mid 30’s expected at 9,500’ accompanied by calm winds. Tonight the temperatures drop off to the teens, but the warm and strong winds will start to pick up from the S-SW at 5-15mph ahead of the next fast moving trough coming to our area on Sunday night. Sunday will be mostly cloudy with snow showers, with the best chance for moisture coming after 5pm. During the day however, winds will be howling from the SW at around 30mph, with higher gusts.

Avalanche Conditions

The story of the last few days has been a wind event and the persistence of cold temps. As a result, these are the two biggest concerns for the day. The last few days has seen the formation of shallow wind slabs on NW-SE aspects that still may be reactive today. Cross-loaded gullies and open pockets near treelne may be the areas that have seen the most loading, so pay special attention to where you encounter some punchier snow conditions. The cold weather has also acted to preserve the instabilities in the snow. However, there are currently no obvious signs of instability that we would normally see in the La Sals after a significant snowfall, such as collapsing, cracking and recent avalanche activity, which combined with snow pit tests makes me feel as though the snowpack isn’t in a very reactive state. The last thing to take note of is that there is now a nice sparkly layer of surface hoar on the snow surface, which, if buried by our next storm may pose a problem later. However, the forecasted winds tomorrow should do there part to destroy the surface hoar before that can happen. Yesterday afternoon saw a brief snow shower which may have covered it up-we will all have to check and see if that happened when we are out there today. So, to boil down my blabbering about the snow, the avalanche danger is MODERATE on wind loaded slopes steeper than 35 degrees. Upper elevation ridges have been heavily scoured and do not have much of a snow pack so the danger there and on shallower slopes below treeline is LOW.

Nordic and Skate Skiing:

A good classic track is packed out into Gold Basin and up to Geyser Pass thanks to the sledders. The road isn’t quite in shape for skating though.

Public Announcements:

We still need volunteers and observers! Call us at the office for more info, 259-7155 for more info, or 636-3363 after hours.

Word of the Day:

Surface Hoar is the large feathery frost that forms on the snow surface during calm, clear, cold and humid conditions. When buried it can be one of the most dangerous weak layers out there.