Avalanche Advisory: Wednesday - Mar 25, 2020

THIS AVALANCHE ADVISORY EXPIRED ON March 26, 2020 @ 6:31 am
Avalanche Advisory published on March 25, 2020 @ 6:31 am
Issued by Steve Mace - ESAC

CONSIDERABLE avalanche danger persists at upper elevations today, and MODERATE danger exists at mid-elevations. Fresh and sensitive wind slabs will be the primary concern today on northerly and easterly aspects near and above treeline. The size and distribution of fresh wind slabs may increase this afternoon if we see significant levels of precipitation throughout the day.  Heightened avalanche conditions exist, conservative decision making, and cautious route-finding is recommended.

3. Considerable

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Above Treeline
Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.

2. Moderate

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

1. Low

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Below Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
    Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.
Avalanche Problem 1: Wind Slab
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    Certain
    Very Likely
    Likely
    Possible
    Unlikely
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    Historic
    Very Large
    Large
    Small

The last few days have brought intermittent showers and continued strong winds. 4” of new snow was recorded in the mammoth area over the last 24 hours. As long as this snow continues to fall and the winds continue to move it around, Wind slabs sensitive to human trigger will be likely.  Wind slabs will vary in size, distribution, and sensitivity today. Fresh sensitive wind slabs are likely to be shallow and sitting on top of older, larger, and more stubborn slabs. NW-N-E-SE aspects at mid and upper elevations will be of greatest concern. Do your own localized assessments and be suspect of terrain features that encourage drifting such as the leeward sides of ridgelines, gully features, and cross-loaded depressions.  Surface clues such as blowing snow, large drifts, dense hollow feeling snow, recent cornice growth, and uneven snow surfaces can help you identify and avoid areas of recent wind deposits.

advisory discussion

The last couple of days of warm temperatures have helped to settle much of the upper snowpack, keeping our focus on surface instabilities. However, It is important to remember that we are still dealing with a shallow snowpack. Shallowly buried rocks and trees remain a significant hazard, particularly at lower elevations. Now is a good time to tone it down. Every care should be taken to avoid injuries and unnecessary risk at this point in time.

Weather and CURRENT CONDITIONS
weather summary

Expect mostly cloudy skies today with cold temperatures and moderate to strong winds out of the southwest. Snow showers are likely to increase through the day with a chance of thunderstorms in the afternoon.

Unsettled weather may continue through the end of the week with intermittent snow showers, cold temperatures, and breezy conditions.  we may see a brief period of warm and drier weather early next week as a weak high-pressure ridge builds over the area, but this may be short-lived and we may see another period of inclement weather later in the week. 

Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 8,000 ft. to 10,000 ft.
Wednesday Wednesday Night Thursday
Weather: Partly cloudy then becoming mostly cloudy. Chance of snow in the morning, then widespread snow showers and slight chance of thunderstorms in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 55%. Mostly cloudy then becoming partly cloudy. Slight chance of thunderstorms in the evening. Scattered snow showers through the night. Snow levels below 7000 feet. Chance of precipitation is 40%. Partly cloudy then becoming mostly cloudy. Snow showers likely through the day. Slight chance of thunderstorms in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 60%.
Temperatures: 23 to 33. deg. F. 7 to 13. deg. F. 21 to 29. deg. F.
Mid Slope Winds: Southwest 15 to 25 mph with gusts to 45 mph. West 15 to 20 mph in the evening becoming light. Gusts up to 45 mph. Light winds. Gusts up to 25 mph in the morning.
Expected snowfall: 70% probability up to 4 inches. 30% probability of 2 to 4 inches. | SWE = up to 0.15 inch. in. 50% probability up to 1 inch. 50% probability no accumulation. | SWE = less than 0.10 inch. in. 60% probability up to 2 inches. 40% probability no accumulation. | SWE = less than 0.10 inch. in.
Over 10,000 ft.
Wednesday Wednesday Night Thursday
Weather: Mostly cloudy. Chance of snow in the morning, then widespread snow showers and slight chance of thunderstorms in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 60%. Mostly cloudy then becoming partly cloudy. Slight chance of thunderstorms in the evening. Scattered snow showers through the night. Snow levels below 7000 feet. Chance of precipitation is 45%. Partly cloudy then becoming mostly cloudy. Snow showers likely through the day. Slight chance of thunderstorms in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 65%.
Temperatures: 13 to 23. deg. F. Zero to 6 above zero. deg. F. 11 to 19. deg. F.
Ridge Top Winds: Southwest 15 to 25 mph with gusts to 40 mph. West 15 to 25 mph with gusts to 40 mph. Light winds.
Expected snowfall: 60% probability of 1 to 4 inches. 40% probability of 2 to 4 inches. | SWE = up to 0.15 inch. in. 60% probability up to 1 inch. 40% probability no accumulation. | SWE = less than 0.10 inch. in. 70% probability up to 2 inches. 30% probability no accumulation. | SWE = up to 0.15 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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