Avalanche Advisory: Wednesday - Mar 13, 2019

THIS AVALANCHE ADVISORY EXPIRED ON March 14, 2019 @ 6:51 am
Avalanche Advisory published on March 13, 2019 @ 6:51 am
Issued by Josh Feinberg - Eastern Sierra Avalanche Center

Strong gusty winds will keep avalanche danger MODERATE at upper elevations due to fresh sensitive and older more stubborn wind slabs.  LOW danger at mid and low elevations doesn’t mean NO danger.  Continue to watch for isolated wind slabs, and recognize the potential for loose-dry sloughs in steep sheltered terrain.   

2. Moderate

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Above Treeline
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.

1. Low

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Near Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

1. Low

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Below Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
    Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
Avalanche Problem 1: Wind Slab
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Winds have been shifting constantly for the past several days, and are back out of the north today with gusts up to 60mph at mid and upper elevations.  Last night SW gusts over Mammoth Mtn were recorded over 100mph.  Small soft wind slab avalanches were reported occuring yesterday in the Solitude Canyon areas near Mammoth.  Greatest concern for fresh sensitive and older more stubborn wind slabs exists at upper elevations, with decreasing concern at lower elevations.  With the shifting winds, all aspects are suspect.  Look for these just below ridgelines, sidewalls of gullies, and in across-slope deposition zones.  Do your own localized assessments of denser wind-deposited snow, and be weary that triggering even a small pocket could lead to a nasty fall in steep consequential terrain.   

Avalanche Problem 2: Loose Dry
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Our recent cold clear weather has kept sheltered snow soft and unconsolidated.  While this is keeping the skiing and riding enjoyable, there were many reports of significant sloughing yesterday in steep terrain. While relatively small, these sloughs can run longer than expected, could sweep a person off their feet, and could have bad consequences if trees, cliffs or gullies are involved. Manage slough wisely or avoid steep sheltered terrain. 

advisory discussion

Besides avalanche concern, firm wind-swept surfaces and melt-freeze crusts can make for challenging travel in exposed areas, and a fall could be hard to self-arrest. Depending on terrain, crampons and ice-ax or whippet are good additions to your kit, along with the knowledge of how to use them.   

recent observations
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-3/12 - Mammoth - Solitude Canyon: Report of a natural and a human triggered soft wind slab avalanche in the banana chute. R1 D1-1.5.

-3/12 - Convict - Mini Morrison:  Handful of natural loose point releases running far down NE chutes.

-3/12 - Bishop Creek - Table Mtn: Wind tansport and small point releases on NE aspects.

-3/12 - June - Negatives and Hemlock: Wind transport and sloughing in sheltered terrain.

-3/12 - Convict - E Face of Morrison: Increasing winds, slight warming of E aspect snow.

-3/12 - Mammoth - Hammil Bowl: High winds.

 

Weather and CURRENT CONDITIONS
weather summary

For today expect sunny skies, cold temperatures reaching the mid 20s around 10,000’, and northerly winds gusting up to 60mph at mid and upper elevations.  

We are starting the longest period of dry weather we’ve had in a LONG time, as high pressure builds and temperatures climb back to what we normally expect for this time of year thru mid next week.  The end of next week looks to be unsettled again. 

Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 8,000 ft. to 10,000 ft.
Wednesday Wednesday Night Thursday
Weather: Sunny. Clear. Sunny.
Temperatures: 25 to 33. deg. F. 9 to 14. deg. F. 32 to 40. deg. F.
Mid Slope Winds: North 15 to 20 mph with gusts to 60 mph. North around 15 mph with gusts to 45 mph in the evening becoming light. Light winds. Gusts up to 25 mph in the morning.
Expected snowfall: 0 in. 0 in. 0 in.
Over 10,000 ft.
Wednesday Wednesday Night Thursday
Weather: Sunny. Clear. Sunny.
Temperatures: 18 to 24. deg. F. 7 to 12. deg. F. 26 to 31. deg. F.
Ridge Top Winds: North 30 to 45 mph decreasing to 25 to 35 mph in the afternoon. Gusts up to 60 mph. North 25 to 35 mph with gusts to 50 mph decreasing to 15 to 30 mph with gusts to 40 mph after midnight. Northeast 15 to 20 mph with gusts to 30 mph.
Expected snowfall: 0 in. 0 in. 0 in.
Disclaimer
This Avalanche Advisory is designed to generally describe avalanche conditions where local variations always occur. This product only applies to backcountry areas located outside established ski area boundaries. The information in this Avalanche Advisory is provided by the Eastern Sierra Avalanche Center, who is solely responsible for its content.

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