Avalanche Advisory: Sunday - Jan 3, 2021

THIS AVALANCHE ADVISORY EXPIRED ON January 4, 2021 @ 6:15 am
Avalanche Advisory published on January 3, 2021 @ 6:15 am
Issued by Steve Mace - ESAC

LOW avalanche danger exists at all elevations. Small isolated pockets of wind slab will be possible to find on NW-N-E-SE aspects particularly in catchment zones near treeline.  The largest hazard remains the thin obstacle-ridden conditions.

1. Low

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

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.
    Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
Avalanche Problem 1: Wind Slab
  • Type ?
  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

Strong to Gale force winds picked up yesterday and continued out of the SW throughout the evening. We may see wind speeds drop off a bit this afternoon, but they should still fit well into the strong category. Despite the continued strong winds, we do not expect significant new slab development today. Upper elevations are not holding a substantial amount of loose snow at the moment. Recent strong winds have already stripped much of the alpine and a few warm and sunny days have helped our snowpack to settle and consolidate. However, strong winds can distribute snow in unexpected ways. Don’t be surprised to find small wind deposits at lower elevations and further down slopes than you may typically expect to find them. Areas that still hold loose surface snow in the mid-elevations band may be the most likely place to find a pocket of reactive wind slab today. Do your own localized assessments and be suspect of terrain features that encourage drifting such as the leeward sides of ridgelines, gully features, and cross-loaded terrain features.

advisory discussion

LOW danger does not mean "NO danger". We still have several hazards to deal with in our snowpack. Be on the lookout for small isolated pockets of unstable snow today.  While the risk of triggering a large avalanche is low, even a small avalanche could result in a very unpleasant ride given the shallow and obstacle-ridden conditions. It is also important that we all continue to track on the weak base to our snowpack. It remains to be seen if the snowfall expected this week will be enough to tip the balance and reawaken the PWL near the ground, but it is certainly something to keep in mind as we receive our first significant load in over 2 weeks.

In addition, the shallow and sporadic coverage continues to pose serious hazards to backcountry enthusiasts. Recent observations from across the range continue to highlight the shallow and obstacle-ridden conditions.  Slow it down and move with caution. The sharks are everywhere, lurking just below the surface.

Weather and CURRENT CONDITIONS
weather summary

Expect mostly cloudy skies and mild temperatures today. Highs are expected in the low to mid 30°F.  Winds have shifted back to the SW and increased in speed. Expect moderate to strong winds with very strong gusts even at lower elevations.

Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 8,000 ft. to 10,000 ft.
Sunday Sunday Night Monday
Weather: Mostly cloudy then becoming partly cloudy. Snow levels below 7000 feet increasing to 7500 feet in the afternoon. Mostly cloudy. Snow levels 7500 feet. Chance of precipitation is 10%. Mostly cloudy. Chance of snow in the morning, then snow in the afternoon. Snow levels 7000 feet. Chance of precipitation is 70%.
Temperatures: 34 to 40. deg. F. 24 to 29. deg. F. 31 to 39. deg. F.
Mid Slope Winds: West 15 to 20 mph with gusts to 40 mph in the morning becoming light. Light winds becoming southwest around 15 mph after midnight. Gusts up to 30 mph. Southwest around 15 mph with gusts to 35 mph increasing to 20 to 30 mph with gusts to 60 mph in the afternoon.
Expected snowfall: 0 in. 0 in. 70% probability of 1 to 5 inches. 30% probability of 5 to 8 inches. | SWE = up to 0.40 inch. in.
Over 10,000 ft.
Sunday Sunday Night Monday
Weather: Mostly cloudy then becoming partly cloudy. Snow levels 7000 feet increasing to 8000 feet in the afternoon. Mostly cloudy. Slight chance of snow showers after midnight. Snow levels 7500 feet. Chance of precipitation is 15%. Mostly cloudy. Chance of snow in the morning, then snow in the afternoon. Snow levels 7000 feet. Chance of precipitation is 90%.
Temperatures: 28 to 34. deg. F. 20 to 25. deg. F. 24 to 30. deg. F.
Ridge Top Winds: West 20 to 35 mph with gusts to 60 mph decreasing to 15 to 25 mph with gusts to 35 mph in the afternoon. Southwest 15 to 25 mph. Gusts up to 30 mph increasing to 40 mph after midnight. Southwest 25 to 35 mph with gusts to 70 mph increasing to 45 to 60 mph with gusts to 95 mph in the afternoon.
Expected snowfall: 0 in. Up to 1 inch. | SWE = less than 0.10 inch. in. 70% probability of 1 to 5 inches. 30% probability of 5 to 10 inches. | SWE = up to 0.45 inch. 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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