Southerly winds have overloaded north-facing slopes and the avalanche danger is CONSIDERABLE on steep slopes facing W-N-E near and above treeline. Human triggered avalanches are likely, and natural avalanches are possible in these areas. Below treeline and on other aspects, the avalanche danger is MODERATE and human triggered avalanches are possible. Backcountry travelers need to have excellent route finding skills. Stay off of and out from under steep, northerly-facing avalanche terrain.
Persistent weak layers of weak, sugary, faceted snow are present on all north-facing aspects at all elevations. Additionally, cold temperatures and a lack of snowfall for most of January has formed weak layers around the compass and elevation zones. With the recent snow, West, Southwest, and Southeast aspects now harbor dangerous slabs overlying weak faceted snow.
Strong southerly winds redistributed snow earlier in the week. Additional wind in the forecast could continue to redistribute snow near and above treeline. Unstable wind drifts 2 to 4' deep will most likely be found on slopes facing W-N-E, and a triggered wind slab will likely step down to a buried weak layer causing a deeper and dangerous avalanche. Wind drifts are often recognizable by their smooth, rounded appearance, or they may sound and feel hollow like a drum. Cracking is a sign of instability. Avoid steep slopes with recent deposits of wind drifted snow.
The Geyser Pass Road is plowed with a snow-packed surface.
The Lower Utah Nordic Alliance (LUNA) groomed all trails on Wednesday. Follow LUNA on Instagram @luna_moab.
Our avalanche beacon training park is up and running for the season. Thanks to Moab Gear Trader and Talking Mountain Yurts for their support of this valuable resource!
We noted yet another natural avalanche that probably ran on 1/24/2021 on an east aspect near treeline in Colorado Bowl. Yesterday Matthew Cozart report several avalanches in the Abajos. Earlier this week, reports of natural avalanches including Exxon's Folly, Snaggletooth Ridge Tukno Shoulder , Horse Creek .
Colorado Bowl with crown and flank remnants in red. Much of this slope appeared to have filled back in after it probably ran on 1/24/201.
24 Hour Snow 0" 72 Hour Snow 3" Base Depth in Gold Basin 39" Wind SE 35 G55 Temp 27F
Yesterday, southerly winds blew in the 25-35 mph range for most of the day. While these winds were consistent, there was not much snow to transport and the forecasted winds failed to materialize. Today, southwest flow overhead will strengthen, driving the deep pacific trough into our area. Look for increasing clouds throughout the day and high temps near 30F. Southwesterly winds will continue to increase, ranging from 30 to 40 mph with gusts to around 50 mph. Isolated rain and snow showers could occur by midday, but the main pulse will occur tonight, with ensemble models estimating 3-5" of snow for the La Sal and Abajo Mountains.
Wind, temperature, humidity on Pre Laurel Peak (11,700')
Snotel site near Geyser Pass Trailhead (9600')
Storm totals at the Gold Basin study plot (10,000')
Snowpack Discussion
In our travels yesterday, the impacts of Wednesday's wind event were evident. In areas below treeline, last weekend's storm snow is less wind-affected. Breaking trail in this soft and somewhat bottomless snow produced 10-20' shooting cracks, and one small test slope (east aspect) produced a soft slab at the new snow/old snow interface. Near treeline, depth is variable and much of the snow has been stiffened by the wind. In these areas, the snow is more supportive and we experienced less cracking and collapsing than we had expected. In areas that have wind-drifted snow, the snowpack is considerably deeper with a moderately dense slab (4F to 1F hardness) overlying weak basal facets (F hardness) above the October and November crusts. Above treeline, large wind drifts and significant cross loading were easily observed on leeward aspects, ranging from west to north to east. Poor snowpack structure still plagues our mountains, with numerous persistent weak layers buried both underneath recent snow, as well as near the bottom of the snowpack. Strong winds have built stiff slabs on these weak layers and may be triggered by the weight of a skier or rider, especially in places where the slab is thin and weak.
Test slope (east aspect) that produced a soft slab at the new snow/old snow interface.
Southerly winds on 1/27/2021 have cross-loaded many slopes above treeline on west, north, and east aspects.
East aspect near treeline with 100 cm snow depth with a moderately dense slab (4F to 1F hardness) overlying weak basal facets (F hardness) above the October and November crusts.
This forecast is from the U.S. Forest Service, which is solely responsible for its content. This forecast describes general avalanche conditions and local variations always occur.
