Manti-La Sal Avalanche Center

US Forest Service Manti-La Sal National Forest

Introduction:

Good Morning! This is Max Forgensi with the USFS Manti-La Sal Avalanche Center with your avalanche and mountain weather advisory. Today is Friday, December 12th, 2003 at 7:30 A.M

General Conditions:

The sky is clear over Moab with a temperature of 17F and calm winds. The Geyser Pass Trailhead is at 14.2F and there is 25” at our snow stake. In Gold Basin, there is a 33” base and there was a trace of snow on the storm stake yesterday afternoon. Could winter be here to stay? Yesterday, the temperature at the trailhead stayed below freezing again. And there is plenty of the fluff below tree-line to get out and enjoy. Just be careful on the road to the trailhead, the road is snow-packed and a few ditches have caught some unsuspecting drivers.

Mountain Weather:

Today: Partly Cloudy, high near 30. Winds out of the NW at 6 mph.

Tonight: Clear. Low around 14. Winds WNW 1-5.

Saturday: Partly Cloudy. High 34, winds calm.

The next best chance for snow in the La Sal Mountains is going to be Sunday night…keep your fingers crossed!

Avalanche Conditions:

Amazing what wind can do. At and above tree line, our snow has been transporting and sublimating (see word of the day below) leaving South and Westward aspects wind blown or bare and creating wind slabs on our North and East aspects. It appears that wind slabs are developing quite close to the ridge line and in the upper parts of starting zones. These slabs are very hard, and vary in depth in only what seemed feet. Be careful up there. Below tree line some open areas were wind hammered as well. Overall, there are no avalanches to report, with no collapsing or cracking and the new snow is settling quite nicely. Our main concern is still with newly deposited wind slabs in upper elevations. I am going to keep the back country danger at or above tree-line at an overall MODERATE, with pockets of CONSIDERABLE on wind loaded slopes (NW-SE) 35 degrees and steeper. In open shady areas below treeline the avalanche danger is MODERATE on slopes steeper than 35 degrees. Caution is still necessary out there, it is still the early season and many obstacles may lie just below the surface of the snow.

Nordic and Skate Skiing:

No time is better than the present for Nordic skiing! Extra blue wax could be the call today.

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:

Sublimation: A weather phenomena when a solid particle, i.e. snow grains, entirely skips the liquid phase and turns into a gas. The amount of snow that either sublimates or transports is directly related to the relative humidity in the atmosphere. Snow has to go some where! It either transports or is lost in the atmosphere due to sublimation. When the relative humidity is high, 85% or greater, the air has enough moisture in it already, so the snow transports to lee sides of mountains when there are moderate winds (15mph or greater) present. When the RH drops, and the winds are moderate, the air sucks up the available moisture. The lower the RH, the more snow will sublimate into the atmosphere. That is why in the La Sal Mountains, you notice that the ridges and mountain tops are bare.