Avalanche Advisory: Thursday - Jan 30, 2020

THIS AVALANCHE ADVISORY EXPIRED ON January 31, 2020 @ 6:43 am
Avalanche Advisory published on January 30, 2020 @ 6:43 am
Issued by Josh Feinberg - Eastern Sierra Avalanche Center

LOW avalanche danger continues at all elevations.  Small pockets of sensitive wind slab developed from yesterday’s very strong northerly winds may exist in isolated areas at mid to upper elevations.  

 

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.
Avalanche Problem 1: Wind Slab
  • Type ?
  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

Snow transport was easily observed yesterday up and down the range as northerly winds were recorded blowing into the 70s over high ridge tops for much of the day before dropping off significantly in the evening. Limited amounts of loose snow will have drastically limited the size and distribution of deposition. Be on the lookout for a small isolated fresh pocket of smooth pillow-like snow on the leeward side of terrain features on cross loaded slopes and the non-northerly side of ridges that weren’t stripped bare prior to yesterday.  While unlikely to be large enough for a burial, triggering a small slab could lead to a bad fall in consequential terrain.  

 
advisory discussion

What, no mention of the loose rotten faceted snow sandwiched between crusts?!  While this weak structure can still be found in many areas throughout the range where a shallower snowpack exists, the chances of an actual slope failure leading to an avalanche is miniscule. Our increased amount of observations across our wide range throughout this past week has increased our confidence to remove this as a potential problem. There are still plenty of places that a snow-pit can be dug to find propagating test results, but the reality of the discontinuous structure across slopes, the lack of contiguous overlying slabs, and dare I say the self-supporting nature of the thicker crusts we have been seeing, make an actual avalanche very unlikely.  But we can never say that avalanches are impossible!  An isolated unsupported slope (such as above a cliff) where an overlying slab lies ontop of just the right structure would be a place to consider avoiding. As always, it’s important to do your own localized assessments, adjust your travel accordingly, and practice safe protocols such as exposing one person at a time.  When (fingers crossed sooner than later!) we actually get a big dump of snow, don’t be surprised to see these weak layer concerns re-emerge.  Please help us by continuing to monitor them and submitting your observations :-).       

 
Weather and CURRENT CONDITIONS
weather summary

Partly clouds skies this morning should clear as temperatures reach the upper 30s near 10,000’.  Expect relatively light north winds with occasional gusts up to 30mph.

 

High pressure will continue to build thru Saturday with increasing spring-like high temperatures, until a significant cold front moves in on Sunday dropping temperatures back down and bringing a slight chance of light snowfall. 

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: Partly cloudy. Snow levels 8000 feet. Chance of precipitation is 0%. Clear. Snow levels 7500 feet decreasing to below 7000 feet after midnight. Chance of precipitation is 0%. Sunny. Snow levels 7000 feet increasing to 8500 feet in the afternoon. Chance of precipitation is 0%.
Temperatures: 37 to 45. deg. F. 24 to 29. deg. F. 44 to 54. deg. F.
Mid Slope Winds: North around 15 mph with gusts to 30 mph. Light winds. Gusts up to 25 mph in the evening. Light winds.
Expected snowfall: 0 in. 0 in. 0 in.
Over 10,000 ft.
Thursday Thursday Night Friday
Weather: Partly cloudy then becoming sunny. Snow levels 7500 feet increasing to 8500 feet in the afternoon. Chance of precipitation is 0%. Clear. Snow levels 7500 feet decreasing to below 7000 feet after midnight. Chance of precipitation is 0%. Sunny. Snow levels 7000 feet increasing to 8500 feet in the afternoon. Chance of precipitation is 0%.
Temperatures: 29 to 37. deg. F. 23 to 29. deg. F. 37 to 45. deg. F.
Ridge Top Winds: North 15 to 25 mph. North 15 to 20 mph with gusts to 30 mph. North 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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