Forecast for the Salt Lake Area Mountains

Mark Staples
Issued by Mark Staples on
Saturday morning, December 22, 2018
New snow and increased winds overnight have created heightened avalanche conditions on any slope with wind drifted snow. You can trigger slabs of wind drifted snow on these slopes making the avalanche danger MODERATE at mid and upper elevations. In isolated locations with wind drifted snow, there remains a chance of triggering an avalanche at the ground. To find good riding conditions and good stability, ride slopes not affected by the wind.
Low
Moderate
Considerable
High
Extreme
Learn how to read the forecast here
Special Announcements
The new UAC IOS mobile app is now available on the app store. Check out the new "My Weather" feature.
Weather and Snow
Snow fell yesterday morning and late last night totaling 4-7 inches (0.2-0.5 inches of water).
Temperatures dropped overnight and are in the mid teens F this morning.
Winds increased overnight and this morning are blowing from the W and NW 15-20 mph gusting 30-45 mph.
Today a short lived ridge of high pressure will move over the area. Skies will slowly clear and winds should ease with temperatures climbing into the low 20's F. More snow should come with another storm system on Monday.
There should be a noticeable ice crust under the new snow on south facing slopes and low elevation slopes where the snow was a bit damp yesterday and now refrozen this morning.
Recent Avalanches
Yesterday afternoon some shallow and small soft slabs of new snow and wind drifted snow produced avalanches at ski areas.
Ad
Avalanche Problem #1
Wind Drifted Snow
Type
Location
Likelihood
Size
Description
Westerly winds increased overnight and should have formed slabs of wind-drifted snow this morning. Look for and avoid these fresh wind slabs under ridge lines and along cross loaded ridges. These slabs could be easy to trigger this morning but are an easy problem to avoid if you look for it.
Another reason to avoid these wind loaded areas is that they may have added just enough weight and stress to the snowpack to cause an avalanche to break on weak faceted snow near the ground. I don't expect this to be an issue in the upper Cottonwood canyons where the snowpack is 3-4 feet deep. I would be more concerned about this issue in other areas where the snowpack is about 2-3 feet deep.
Avalanche Problem #2
New Snow
Type
Location
Likelihood
Size
Description
Pay attention to how the new snow feels under you feet and how it is bonded to the underlying snow surface. In many places the new snow landed on several inches of graupel that fell on Wednesday but should be well bonded today. In some places underneath very steep slopes, that graupel snow may have rolled downhill and made a thick layer of graupel that may not be well bonded yet. In these isolated places, you could get a shallow soft slab of new snow to release. Otherwise, the new snow may just sluff in very steep terrain.
General Announcements
This information does not apply to developed ski areas or highways where avalanche control is normally done. This forecast is from the U.S.D.A. Forest Service, which is solely responsible for its content. This forecast describes general avalanche conditions and local variations always occur.