Avalanche Advisory: Friday - Jan 10, 2020

THIS AVALANCHE ADVISORY EXPIRED ON January 11, 2020 @ 6:34 am
Avalanche Advisory published on January 10, 2020 @ 6:34 am
Issued by Steve Mace - ESAC

The avalanche danger is LOW at all elevations today. While generally safe avalanche conditions exist, it will not be impossible to find areas of unstable snow on isolated terrain features and in extreme terrain. Be on the lookout for isolated areas of fresh wind slab development at mid and upper elevations today.

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
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    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

A brief winter storm yesterday brought 0.5” of new snow to the Mammoth area with strong winds out of the NE.  While snow totals from this storm are minimal it will not be impossible to find isolated areas of fresh wind slab development on easterly, southerly, and westerly aspects at mid and upper elevations.  Use Surface clues to help you identify areas of concern and use caution when evaluating terrain features such as the leeward side of ridgelines, confined couloirs, and unsupported slopes. While finding a consequential avalanche today will be unlikely, realize that even a very small avalanche has the potential to knock you off your feet and carry you through unpleasant terrain. 

advisory discussion

In times of LOW avalanche danger, it remains important to evaluate terrain choices carefully and to practice safe travel techniques.  If you decide to venture into the backcountry today the biggest hazard may well be the hard, slick snow surface present throughout much of the range.  Recent field observations have identified slide-for-life conditions in many exposed areas. A dusting of new snow could very well exasperate this hazard. An ice ax and boot or ski crampons may be necessary tools today if you decide to venture above treeline. 

It is also important to keep track of surface conditions and think about the impact they will have after our next big storm.  As a wise human once said "today's snow surface is tomorrow's weak layer." Field observations continue to highlight facet crust combos in the upper snowpack as well as surface faceting in shaded and protected areas throughout the forecast area. In the short term, our cold clear weather has helped to break down crusts and keep surface conditions somewhat soft. However, when we see our next load of significant precipitation this structure may increase the sensitivity of resulting avalanches. 

Weather and CURRENT CONDITIONS
weather summary

 Expect sunny skies, warm temperatures, and moderate northerly winds during daylight hours today.  As evening approaches, the winds should shift to the SW and increase dramatically. Ridgetop gusts are expected to reach over 100 MPH after midnight.

For tomorrow, expect partly cloudy skies, temperatures in the mid 20’s, and intermittent snow showers. Strong to extreme winds will continue out of the southwest for most of the morning, decreasing substantially by the afternoon.

Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 8,000 ft. to 10,000 ft.
Friday Friday Night Saturday
Weather: Sunny. Partly cloudy then becoming clear. Partly cloudy. Chance of snow. Snow levels below 7000 feet. Chance of precipitation is 25%.
Temperatures: 34 to 42. deg. F. 18 to 23. deg. F. 26 to 34. deg. F.
Mid Slope Winds: West around 15 mph with gusts to 40 mph. Southwest 15 to 25 mph with gusts to 55 mph increasing to 25 to 40 mph with gusts to 85 mph after midnight. Southwest 30 to 40 mph with gusts to 80 mph becoming west 20 to 30 mph with gusts to 60 mph in the afternoon.
Expected snowfall: 0 in. 0 in. 30% probability up to 1 inch. 70% probability no accumulation. | SWE = less than 0.10 inch. in.
Over 10,000 ft.
Friday Friday Night Saturday
Weather: Sunny. Partly cloudy then becoming clear. Partly cloudy. Chance of snow. Snow levels below 7000 feet. Chance of precipitation is 25%.
Temperatures: 27 to 35. deg. F. 12 to 17. deg. F. 20 to 26. deg. F.
Ridge Top Winds: Northwest 15 to 30 mph with gusts to 50 mph. Southwest 25 to 35 mph with gusts to 65 mph increasing to 50 to 70 mph with gusts to 100 mph after midnight. Southwest 50 to 70 mph with gusts to 100 mph becoming west and decreasing to 25 to 40 mph with gusts to 60 mph in the afternoon.
Expected snowfall: 0 in. 0 in. 30% probability up to 1 inch. 70% probability no accumulation. | SWE = less than 0.10 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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