Bollettino valanghe

Salt Lake

Pubblicato il Feb 18, 2022valido fino al Feb 19, 2022Utah Avalanche Center

Pericolo valanghe

Alta quota
Limite del bosco
Sotto il limite del bosco

Non aggiornato — questo bollettino è scaduto 5 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

The avalanche danger is LOW and avalanche conditions are generally safe, with shallow loose dry avalanches and minor sluffing on the steepest slopes the primary avalanche concern. Across upper-elevation terrain that allows for drifting snow to accumulate, there could be shallow fresh slabs of wind drifted snow.

The snow on southerly-facing slopes shouldn't heat up too much today to cause widespread wet avalanches, but pay attention to changing conditions and be prepared to alter your plans. If the snow surface is becoming damp, it's time to leave or change your aspect.

Problemi valanghivi

Storm Slabs
N
NE
E
SE
S
SW
W
NW
Alta quota
Limite del bosco
Sotto il limite del bosco
Probabilità
Possible
Dimensione
1
Since Tuesday night, the Cottonwoods got anywhere between 5-9.5 inches of light snow that have fallen on an array of snow surfaces in the backcountry. In areas sheltered from the northwest winds, I would expect to continue seeing shallow new snow avalanches today. The primary concern will be fast-running sluffs in steep terrain. Any area that still held any lingering weak, faceted snow before the storm will be more suspect for some shallow soft slabs to begin forming. Remember that even a small avalanche can be problematic in very steep and complicated terrain. Think about the terrain you are traveling above today. While temperatures are climbing, it is still only February and the sun isn't at its full intensity yet. For that reason, snow on southerly-facing slopes shouldn't heat up too much today to cause widespread wet avalanches, but pay attention to changing conditions and be prepared to alter your plans. Pinwheels, rollerballs, and small point releases are signs that the snow surface is becoming damp, and it's time to leave or change your aspect.
Wind Slabs
N
NE
E
SE
S
SW
W
NW
Alta quota
Limite del bosco
Sotto il limite del bosco
Probabilità
Unlikely
Dimensione
1
The low desnity snow combined with increasing northwest winds should create some soft slabs of wind drifted snow at upper elevations, and even some mid-elevation terrain features such as sub-ridges and gullies. These wind slabs will be shallow and overall small in size, but these new wind drifts are sitting atop of weak faceted snow or a firm snow surface, which will make them very sensitive and cause them to run far and fast. Even a small avalanche would be enough to knock a person off their feet and through complex terrain. Look for any slopes with signs of wind drifted snow, and avoiding those slopes. Wind-affected snow often looks wavy, rounded, pillowy, and can sound hollow when walking or riding on it.

Recent Activity

Yesterday, ski resorts and backcountry travelers reported easy sluffing and loose dry avalanches within the new snow, and very few sensitive wind drifts at the upper elevation ridgelines.

One party did trigger a small wet loose avalanche on Superior around 10:15 AM when the sun came out. These avalanches occurred in the Two Trees zone, at 9700' on an East aspect. It broke 6" within the cold new snow and 20' wide.

Greg Gagne's Week in Review is published and can be found HERE.

Snow and Weather

This morning: Under mostly clear skies, there is a temperature inversion in the mountains ranging from the low teens F at ridgelines and in the single digits at trailheads. Winds increased overnight, and are blowing from the northwest averaging 5-15 mph gusting to the mid-20s at mid-elevations, at upper elevation ridgelines wind speeds are averaging 20-25 mph with gusts in the upper 30s mph. Overnight upper elevation ridgelines got gusts up to 55 mph.

Today: Skies will become mostly sunny, and the Northwest winds will continue throughout the day. Expect mountain temperatures to climb into the upper 20s and low 30s F. The northwest winds will average 5-15 mph, with gusts up to 25 at mid-elevations. At upper elevation ridgelines, the winds will average 20-30 mph and gust up to 40 mph this afternoon.

Looking ahead: The weekend will have dry and cool weather. Another storm should arrive late Sunday night or early Monday morning. This one looks more promising.

Wednesday's storm capped a wide variety of snow surfaces which will determine future avalanche conditions as more new snow accumulates. Between Tuesday evening and Thursday morning, 5-9.5 inches of new snow (0.20-0.41 H2O) has fallen, favoring Little Cottonwood Canyon. There is an incredible amount of variability in the old snow surface which consists of weak facets, crusts of varying thicknesses and hardnesses, wind-eroded and sculped snow, and some areas are simply covered in tracks.

The challenge in the future is that having such a wide variety of snow surfaces means there will be a wide variety of stability from slope to slope and the pattern will be complex and tricky to map. With more cold temperatures in the forecast, the new snowfall may begin to weaken and facet at the surface, continuing to add to the wide variety covering the range. Pay attention to the changing snow surfaces before the next storm system.

Mark and Trent went into White Pine yesterday and found a wide variety in the now buried snow surfaces, find the full observation HERE.

General Announcements

Who's up for some free avalanche training? Get a refresher, become better prepared for an upcoming avalanche class, or just boost your skills. Go to https://learn.kbyg.org/ and scroll down to Step 2 for a series of interactive online avalanche courses produced by the UAC.

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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.

Observations and Avalanches

Backcountry Emergency Procedures