Avalanche Advisory: Friday - Jan 22, 2021

THIS AVALANCHE ADVISORY EXPIRED ON January 23, 2021 @ 6:45 am
Avalanche Advisory published on January 22, 2021 @ 6:45 am
Issued by Chris Engelhardt - Eastern Sierra Avalanche Center

LOW Avalanche danger exists Friday. If new snow accumulations pick up today (chance of ~3”), watch for fresh Wind slab primarily on Northerly-Easterly terrain in the alpine and at tree line. Be aware that Hazard may elevate if snowfall exceeds expectations. The overall lack of coverage with abundant obstacles and poor surface conditions consisting of sastrugi, breakable crust and ultra-firm panels remains the greatest hazard.

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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  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
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If we pick up the high end of the snow forecast through Saturday morning (combined with loading SW winds) we may have a decent amount of snow to potentially build wind slab on W-N-E facing terrain in the alpine and middle elevations. Identify terrain that is conducive to capturing wind transported snow such as leeward deposition zones adjacent to ridge line, cliff bands, and gullies that may become cross loaded. There is not a lot of confidence with the snow forecast so it could go either way with little accumulation to potentially 3” today, so do your own analysis in the field and see what actually transpires. The greatest danger likely is a bit of new snow hiding the plethora of obstacles and the potential for a small wind pocket of snow to catch you off guard and drag you through them.

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1/21 – Mammoth Area – San Joaquin Ridge – degraded conditions

1/21 – Mammoth Area – Red Cone Area – thin and dangerous conditions

1/21 – Mammoth Area –Lakes Basin – snow conditions

1/20 – Mammoth Area – Hammil Bowl zone – snow conditions

1/19 – June Lk Area – Snow & weather conditions - Negatives

 

Weather and CURRENT CONDITIONS
weather summary

The main news is the chance of snow this afternoon with a waffling 50% chance of ~3" or a bit more with similiar snowfall predictions for tonight into Saturday morning. SW winds (15-30mph) will return to the area with gusts reaching 50mph at ridge top. Wind direction is predicted to switch back to the North by Saturday morning. Temperatures will be cooler than yesterday, but still could reach 35Fdeg in the upper elevations. Partly cloudy conditions are expected ahead of the snowfall that is predicted for later today and into tonight. The pattern is supposed to remain active through the next 7 days, so snow lovers should put out the good vibes.

 

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. Chance of snow in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 55%. Mostly cloudy. Chance of snow. Snow levels below 7000 feet. Chance of precipitation is 45%. Mostly cloudy. Chance of snow. Snow levels below 7000 feet. Chance of precipitation is 45%.
Temperatures: 25 to 35. deg. F. 13 to 19. deg. F. 21 to 29. deg. F.
Mid Slope Winds: Southwest 15 to 30 mph with gusts to 50 mph. Southwest around 15 mph with gusts to 45 mph in the evening becoming light. Light winds becoming north around 15 mph with gusts to 30 mph in the afternoon.
Expected snowfall: 50% probability up to 3 inches. 50% probability no accumulation. | SWE = less than 0.10 inch. in. 60% probability up to 3 inches. 40% probability no accumulation. | SWE = up to 0.15 inch. in. 40% probability up to 2 inches. 60% probability no accumulation. | SWE = less than 0.10 inch. in.
Over 10,000 ft.
Friday Friday Night Saturday
Weather: Partly cloudy then becoming mostly cloudy. Snow likely in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 65%. Mostly cloudy. Chance of snow. Snow levels below 7000 feet. Chance of precipitation is 50%. Mostly cloudy. Chance of snow. Snow levels below 7000 feet. Chance of precipitation is 45%.
Temperatures: 18 to 26. deg. F. 6 to 12. deg. F. 13 to 19. deg. F.
Ridge Top Winds: Southwest 25 to 35 mph with gusts to 60 mph decreasing to 15 to 30 mph with gusts to 45 mph in the afternoon. Southwest 15 to 20 mph with gusts to 35 mph. Light winds becoming north 15 to 20 mph with gusts to 30 mph in the afternoon.
Expected snowfall: 50% probability up to 3 inches. 50% probability no accumulation. | SWE = less than 0.10 inch. in. 60% probability of 1 to 3 inches. 40% probability no accumulation. | SWE = up to 0.15 inch. in. 50% probability up to 1 inch. 50% 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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