Avalanche Advisory: Tuesday - Feb 11, 2020

THIS AVALANCHE ADVISORY EXPIRED ON February 12, 2020 @ 6:38 am
Avalanche Advisory published on February 11, 2020 @ 6:38 am
Issued by Chris Engelhardt - Eastern Sierra Avalanche Center

LOW avalanche danger exists at all Elevations. Monitor for small wind slabs deposited from gale force E-N winds which have erratically loaded snow on a variety of aspects in isolated terrain features or extreme terrain.

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

Winds are orienting a bit more from the North than the NE today, which will redistribute snow in complex alpine terrain. Although we only saw scant new snow totals this weekend, these trace amounts combined with extreme wind velocities and erratic loading patterns can deposit small wind slabs in isolated terrain features and on a multitude of aspects.  Slightly warming temperatures, N winds, and ever intensifying solar input as the days get progressively longer, may also play a role in loosening up wind deposits on Southerly aspects the next few days.

Cross loaded couloirs and gullies may present the most viable area to collect newly transported snow, so think about the big picture and how even distant terrain and small slides/rock fall could affect you and your position. Identify surface deposits such as ribbons of new snow and pillows adjacent to rock outcroppings and cliff bands, to help get a sense if these conditions could threaten you from above.

advisory discussion

Small avalanches in extreme terrain remain a possibility even within the constructs of “Low Avalanche Danger”. Remember that “Low” does not mean “NO” avalanche hazard, as mountain weather and terrain is dynamic, ever changing, and adjusting to climatic factors and gravitational pull. Although we have not seen any significant snowfall for a long time, lingering small instabilities or just a bit of loosening snow or rock fall can cause a small slide. Pay particular attention, if travelling in tight or confined terrain, where even a small slide may produce enough volume to seriously injure you or cause a bad fall.

Biggest hazards remain inconsistent snow surfaces including breakable crust, loose faceted unsupportable areas, and sections of firm wind board. As we continue to lose snow through wind effects and warming, obstacles are becoming more and more numerous with every passing day. 

recent observations
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2/10- June Lk Area –Negatives/Hemlock -  2-3” new snow

2/10 – Mammoth Area- Punta Bardini –snow conditions

2/9 – Convict Lk Area – Laurel Mtn/Mendenhall couloir –Loose snow Avalanche & Rockfall

2/9- Mammoth Area- Sherwins –snow conditions

Weather and CURRENT CONDITIONS
weather summary

Although lessening a bit, moderate to strong Northerly winds will continue Tuesday with velocities in the 20-35 mph range with gusts reaching 60mph for the high country. Sunny conditions will prevail with temperatures warming up a bit from yesterday with 26-31F in the higher mountains and trending warmer with 32-42F below 10,000ft. Hope of any measurable precipitation in the near future unfortunately does not look promising.

Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 8,000 ft. to 10,000 ft.
Tuesday Tuesday Night Wednesday
Weather: Sunny. Snow levels below 7000 feet. Chance of precipitation is 0%. Clear. Snow levels below 7000 feet. Chance of precipitation is 0%. Partly cloudy. Snow levels below 7000 feet. Chance of precipitation is 0%.
Temperatures: 32 to 42. deg. F. 19 to 24. deg. F. 33 to 43. deg. F.
Mid Slope Winds: North 15 to 20 mph with gusts to 40 mph. Northwest around 15 mph with gusts to 30 mph. West around 15 mph in the morning becoming light. Gusts up to 30 mph.
Expected snowfall: 0 in. 0 in. 0 in.
Over 10,000 ft.
Tuesday Tuesday Night Wednesday
Weather: Sunny. Snow levels below 7000 feet. Chance of precipitation is 0%. Clear. Snow levels below 7000 feet. Chance of precipitation is 0%. Partly cloudy. Snow levels below 7000 feet. Chance of precipitation is 0%.
Temperatures: 26 to 31. deg. F. 16 to 21. deg. F. 28 to 33. deg. F.
Ridge Top Winds: North 20 to 35 mph with gusts to 60 mph. Northwest 15 to 25 mph with gusts to 35 mph. Northwest 15 to 25 mph. Gusts up to 35 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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