Avalanche Advisory: Friday - Feb 8, 2019

THIS AVALANCHE ADVISORY EXPIRED ON February 9, 2019 @ 6:41 am
Avalanche Advisory published on February 8, 2019 @ 6:41 am
Issued by Chris Engelhardt - Eastern Sierra Avalanche Center

The avalanche danger is MODERATE at upper elevations and LOW for mid to lower elevations today. Freshly developed WIND SLAB on Northerly aspects will be the main concern. With projected snowfall starting this evening, mid elevations will increase to MODERATE danger overnight. Be on the lookout for fresh sensitive pillows and loaded snow on lee aspects.

2. Moderate

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

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.
    Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
Avalanche Problem 1: Wind Slab
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    Certain
    Very Likely
    Likely
    Possible
    Unlikely
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    Historic
    Very Large
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Moderate to strong Southerly winds overnight and through out  today will produce fresh wind slab on NORTHERLY aspects.  Fresh wind slab will be developing  in upper elevations with complex terrain condusive to capturing sow. These moderate 15-25mph winds are perfect for distributing significant amounts of snow near and adjacent to the top of ridges, cross-loaded gullies and catchment zones. There is plenty of transportable snow out there, so pay attention if there is blowing snow in your area or ski objective.  Avoid skiing over terrain traps such as depressions and gully features  and be on the look out for red flags such as shooting cracks or recent avalanche activity.

advisory discussion

There has been some electricity in the air amongst the ski community with the huge snow totals of late with nearly 10 inches of snow water equivalent (SWE) and close to 7-8 feet  of total snowfall this past weekend.  To say the least, the skiing has been phenomenal and the new storm has settled rapidly. Soft deep turns on virtually every aspect has been the norm except for high elevation wind shorn terrain. The magnitude of the storm helped clean out some of the residual weakness found in shallower areas of the snowpack throughout the eastside where every major drainage, basin, and mountain saw natural avalanche activity during the storm cycle.  Nearly every avalanche looked as if it slid mid-storm and most slides were significantly filled in by post-event snowfall.  With expected snowfall and moderate winds Friday night, avalanche conditions could elevate to MODERATE and even CONSIDERABLE in the mid to upper elevations if snow totals with continued southerly winds  exceed expectations tonight. Do some homework on weather and snow totals if your planning on getting out super early Saturday morning.

SKIING WITH A BUDDY is still highly recommended in regards to deep snow immersion. Falling headfirst in a tree well right now could be very hazardous. The key thing is to have a partner first who could help you get out, and not to panic, try to maintain a good airway to breath, and slowly dig yourself out in a planned concerted effort.

recent observations
Submit Snowpack Observations
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2/07 - Bishop Area –Mt Tom-snow conditions

2/07 - Convict Area –Recent Avalanche Activity and snow conditions

2/06 – 395 Corridor and June Lake area snow conditions

2/06 - Mammoth Area –Mammoth Rock – snow conditions

Weather and CURRENT CONDITIONS
weather summary

After two days of clear blue skies, Friday is forecasted to be partly cloudy turning to mostly cloudy with cold temperatures (High of 20F for upper elev and 30F mid/low elev). Snow could start flurrying in the afternoon and is projected to increase to stormy and snowy conditions beginning Friday evening into the night. Be prepared for cold conditions today with moderate to strong southerly winds today causing negative wind-chill values (-20F). 3-8” of snow are on tap for tonight and this combined with moderate to strong southerly winds could produce much deeper pockets  by Saturday morning. There should be a slight break during the day Saturday before another wave of snow comes back in Saturday night along with cold temperatures.

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: Partly cloudy then becoming mostly cloudy. Slight chance of snow in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 15%. Cloudy. Chance of snow in the evening, then snow after midnight. Snow levels below 7000 feet. Chance of precipitation is 100%. Cloudy. Chance of snow. Snow levels below 7000 feet. Chance of precipitation is 75%.
Temperatures: 22 to 30. deg. F. 9 to 17. deg. F. 20 to 28. deg. F.
Mid Slope Winds: Southwest around 15 mph with gusts to 45 mph. South around 15 mph with gusts to 35 mph. Southwest 15 to 30 mph. Gusts up to 35 mph increasing to 50 mph in the afternoon.
Expected snowfall: No accumulation. | SWE = trace amounts. in. 80% probability of 3 to 7 inches. 20% probability of 7 to 10 inches. | SWE = 0.15-0.40 inch. in. 80% probability of 1 to 3 inches. 20% probability up to 1 inch. | SWE = up to 0.15 inch. in.
Over 10,000 ft.
Friday Friday Night Saturday
Weather: Partly cloudy becoming mostly cloudy. Slight chance of snow in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 15%. Cloudy. Snow likely in the evening, then snow after midnight. Snow levels below 7000 feet. Chance of precipitation is 100%. Cloudy. Snow likely. Snow levels below 7000 feet. Chance of precipitation is 75%.
Temperatures: 15 to 21. deg. F. Zero to 7 above zero. deg. F. 12 to 18. deg. F.
Ridge Top Winds: South 20 to 35 mph with gusts to 50 mph. South 20 to 30 mph with gusts to 50 mph. Southwest 20 to 30 mph with gusts to 45 mph increasing to 25 to 40 mph with gusts to 60 mph in the afternoon.
Expected snowfall: No accumulation. | SWE = trace amounts. in. 90% probability of 4 to 8 inches. 10% probability of 8 to 11 inches. | SWE = 0.25 to 0.50 inch. in. 80% probability of 1 to 4 inches. 20% probability up to 1 inch. | SWE = 0.05 to 0.20 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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