Avalanche forecast

Central Sierra Nevada

Issued Mar 20, 2023valid to Mar 21, 2023Sierra Avalanche Center

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Avalanche danger

Tue

Alpine

2 · Moderate

Treeline

2 · Moderate

Below

2 · Moderate

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Out of date — this forecast expired 3 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Today, people could still trigger avalanches where slabs of wind-blown snow exist on open slopes near ridges and gullies and on steep slopes in sheltered areas where storm snow has not bonded to the old snow. Strong sun this afternoon could make it easier to trigger an avalanche and may cause some wet snow to slide downhill. Move to terrain not steep enough for snow to slide downhill if you see signs of unstable snow, like recent avalanches or cracking in the snow surface, or if you have any doubt about the slope's stability.

Avalanche problems

Wind Slabs
N
NE
E
SE
S
SW
W
NW
Alpine
Treeline
Below treeline
Likelihood
Possible
Size
1–2
Triggering a wind slab remains possible today, where strong SW winds have loaded snow onto leeward-facing slopes near ridges, open wind-exposed slopes, and gullies. The winds will remain strong enough to blow snow today and may keep piling wind-blown snow onto these wind slabs in some places. The most fragile wind slabs exist on near and above treeline NW-N-NE-E-SE aspects. Wind slab avalanches could involve enough snow to bury or injure a person. New cornices will exist along ridges and above wind-loaded slopes. As the sun comes out this afternoon, it could make wind slabs easier to trigger on sunny slopes.

Recent avalanches, blowing snow, cracking in wind-blown snow, and new cornices indicate the presence of unstable wind slabs. If you see signs of unstable wind slabs, bypass those areas for more sheltered slopes without signs of wind-loading.
(3/19/2023)

Ski kicks on the ridge above this wind-loaded slope triggered this wind slab avalanche on Elephant's Hump.
Photo: Public
Storm Slabs
N
NE
E
SE
S
SW
W
NW
Alpine
Treeline
Below treeline
Likelihood
Possible
Size
1–2
Storm slab avalanches also remain possible today due to poor bonding between the old snow surfaces and the new storm snow. In some places, the fresh snow may not have enough cohesion to fail as a slab, and it may slide off the old crusts as loose snow. In other places, the new snow may fail as a storm slab. Unstable storm slabs could linger on any steep slope including below treeline slopes and other typically sheltered areas. This afternoon, strong sun on new snow could make it easier to trigger storm slabs on sunny slopes.

Look for cracking in the storm snow and feel for different layers of snow as you travel through the terrain. If you see any signs of storm snow weakness or doubt a slope's stability, move to lower-angle, non-avalanche terrain.
(3/19/2023)

Ski cuts on below treeline terrain produced dry loose avalanches on Incline Lake Peak.
Photo: SAC
Loose Wet
N
NE
E
SE
S
SW
W
NW
Alpine
Treeline
Below treeline
Likelihood
Possible
Size
1–2
When the strong March sunshine comes out this afternoon, it could provide enough warming for some wet loose avalanche activity on steep slopes. Some of these could entrain enough snow to cause problems, and terrain traps like gullies, cliffs, or creeks would amplify the potential consequences. Areas that stay cloudy and cool will have less potential for wet snow problems.
(3/19/2023)

Skier triggered wet loose avalanche on the lower elevations of Mt. Judah.
Photo: Public

Avalanche Discussion

Yesterday observers reported a small wind slab avalanche on Elephant's Hump and cracking in wind-loaded areas on Elephant's Hump and Incline Lake Peak by midday.
Ski cuts on steep test slopes on Jakes and Incline Lake Peak caused sluffs of loose storm snow that slide on top of the old snow surfaces (crusts or the thin layer of old snow above the crusts).
A wet loose avalanche also released in response to a skier on a steep slope around 7000 ft in the Mt. Judah area yesterday.

Regions covered