Avalanche Advisory: Thursday - Feb 7, 2019

THIS AVALANCHE ADVISORY EXPIRED ON February 8, 2019 @ 6:26 am
Avalanche Advisory published on February 7, 2019 @ 6:26 am
Issued by Steve Mace - ESAC

CONSIDERABLE avalanche danger exists at upper elevations while MODERATE danger exists at lower and mid elevations.  Fresh, sensitive wind slabs will be the primary concern today. Dangerous avalanche conditions remain throughout the forecast zone; careful snowpack evaluation and conservative decision-making is recommended.

3. Considerable

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Above Treeline
Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.

2. Moderate

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

2. Moderate

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Below Treeline
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
    Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.
Avalanche Problem 1: Wind Slab
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Winds have shifted around the compass the last two days, and significant transport was noted yesterday throughout the range.  Expect to find sensitive wind-loaded slopes at upper and mid elevations where terrain features encourage drifting such as the leeward sides of ridgelines or the sidewalls of gullies.  While more southerly and easterly terrain received the lion’s share of distribution yesterday, it will still be possible to find wind slabs on all aspects and even in isolated areas at lower elevations. Use surface clues such as new cornice growth, blowing snow, and uneven snow surface to identify and avoid wind-loaded areas over 35°.  

It’s also important to keep in mind that cornices created by the strong southerly winds over the weekend are likely large and may be sensitive.  Cornices can be unpredictable and deadly. Give them a wide berth and be cautious if traveling adjacent to or underneath large fresh cornices. 

Avalanche Problem 2: Storm Slab
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Recent observations suggest that our snowpack is accepting the new load very well.  While storm slabs will be stubborn and difficult to trigger it will not be impossible to find residual storm instabilities. Wumphing, shooting cracks and recent avalanches are all signs of nearby hazard.  Avoid areas where terrain features increase the consequence of an avalanche. 

advisory discussion

Mostly the snowpack seems to be adjusting to last weekend’s storm snow well.  Recent observations have found a right side up snowpack and increasing stability.  One of the most significant hazards right now is the risk of deep snow emersion, particularly near trees.  Surface snow is unconsolidated and deep, and tree wells are particularly concerning.  Keep your partners close and remember that even an otherwise benign fall could prove deadly.  

Weather and CURRENT CONDITIONS
weather summary

Another day of mild weather is on tap for today with sunny skies this morning becoming mostly cloudy this afternoon.  Winds will be light out of the west with gusts reaching 25 on ridge tops, and temperatures will rise into the low 20s at upper elevations.  Temperatures will be cold again tonight dipping into the single digits. Skies will remain cloudy, and winds will increase to moderate and shift to the southwest.

Tomorrow will be mostly sunny with a chance of snow in the afternoon as another winter storm moves into the area.  Temperatures will be in the mid-teens to low 20s and winds will shift back to the south, gusting to 50 mph on ridge tops.

Precipitation predictions are mixed, but it looks like the bulk of the storm will arrive on Saturday and continue into Sunday.

Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 8,000 ft. to 10,000 ft.
Thursday Thursday Night Friday
Weather: Sunny then becoming mostly cloudy. Mostly cloudy then becoming partly cloudy. Mostly sunny. Slight chance of snow in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 15%.
Temperatures: 25 to 31. deg. F. 5 to 11. deg. F. 22 to 30. deg. F.
Mid Slope Winds: Light winds. Light winds becoming southwest around 15 mph with gusts to 30 mph after midnight. Southwest around 15 mph with gusts to 45 mph.
Expected snowfall: None in. None in. None in.
Over 10,000 ft.
Thursday Thursday Night Friday
Weather: Sunny then becoming mostly cloudy. Mostly cloudy then becoming clear. Mostly sunny. Slight chance of snow in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 20%.
Temperatures: 18 to 23. deg. F. Zero to 5 above zero. deg. F. 15 to 21. deg. F.
Ridge Top Winds: West around 15 mph. Gusts up to 25 mph in the afternoon. Southwest 15 to 25 mph. Gusts up to 25 mph increasing to 40 mph after midnight. South 20 to 35 mph with gusts to 50 mph.
Expected snowfall: None in. None in. None 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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