Avalanche Advisory: Tuesday - Feb 5, 2019

THIS AVALANCHE ADVISORY EXPIRED ON February 6, 2019 @ 6:51 am
Avalanche Advisory published on February 5, 2019 @ 6:51 am
Issued by Steve Mace - ESAC

HIGH Avalanche Danger exists at all elevations today.   Continued heavy snowfall coupled with strong southwest winds has created hazardous conditions. Large natural and human triggered Avalanches are very likely.  Travel in, near or underneath avalanche terrain is not recommended.

4. High

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Above Treeline
Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.

4. High

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Near Treeline
Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.

4. High

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Below Treeline
Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.
    Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.
Avalanche Problem 1: Wind Slab
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Sustained strong SW winds have accompanied the last few days of very heavy snow with gusts reaching well over 100mph yesterday even at mid elevations.  As strong winds continue today expect large fresh wind slab development in areas where terrain features encourage drifting such as the leeward sides of ridgelines and the sidewalls of gullies.  Use surface clues such as new cornice growth, blowing snow, and uneven snow surface to identify and avoid wind-loaded areas.  It is important to keep in mind that recent extreme winds have distributed snow in unpredictable ways.  It will be possible to find isolated areas of wind deposit in places you may not normally expect such as further down slopes and in more protected areas even at lower elevations.

Avalanche Problem 2: Storm Slab
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Well over 6’ of new snow has fallen over the last four days in some areas, with our heaviest precipitation rates recorded over the last 24 hr.  Large storm slab avalanches will be likely today particularly in areas protected from the wind.  Watch for signs of instability such as shooting cracks, wumphing or recent avalanche activity.  Travel on or underneath slopes greater than 30° is not recommended.

Avalanche Problem 3: Loose Dry
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Cold temperatures have led to very low-density snowfall.  With over 2’ of new snow last night and another 10” expected today, loose dry avalanche activity will be very likely on steep slopes.  These loose unconsolidated sloughs could easily be large and entrain enough snow to carry and bury you.   It’s also possible that loose dry activity on the surface could step down and trigger a much larger storm slab avalanche.  

advisory discussion

As the storm starts to decrease in intensity this afternoon it is essential to keep in mind that we just received a significant load. Avalanches today are likely to be very large, running long distances potentially into areas usually thought of as safe.  Be on alert and think about the terrain that is above you. Travel in these conditions is likely challenging and exhausting; an otherwise benign fall in unconsolidated snow comes with the real risk of deep snow emersion today.   

In addition, be on the lookout around town, snow sliding on heavily loaded roofs and road cuts could pose a real hazard today.  

recent observations
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2/4- Bishop Creek, Table Mountain conditions

2/4- Mammoth Area, conditions near town

2/4- Mammoth Area, Wumphing in the Watertank glades

2/3- Mammoth Area, recent avalanche activity, Old Mammoth rd

2/3- Mammoth Area, Very strong winds in the Sherwins

2/3- Red Mountain Snow conditions

Weather and CURRENT CONDITIONS
weather summary

* Winter Storm Warning is in effect until 4 pm today

Periods of snow and gusty winds will continue through the day.  4- 10” of new snow is expected today with 75mph gusts out of the southwest expected at ridge tops.  Temperatures are expected to be cold today with highs expected in the single digits at upper elevations.   Things will taper off tonight as the storm moves out of the area.  Expect partly cloudy skies and decreasing winds this evening.   Bundle up if you head outside these evening, temperatures tonight are expected to dip below zero.  

Sunny skies and mild weather return to the area tomorrow, expect to see partly cloudy skies in the morning becoming clear in the afternoon.  Temperatures will remain cold with a high around 20° as the winds shift to the northwest gusting to 35mph.  

 

Enjoy the sun the next couple of days, another round of new snow is expected this weekend.

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: Cloudy. Snow showers. Snow levels below 7000 feet. Chance of precipitation is 100%. Mostly cloudy. Chance of snow showers in the evening. Snow levels below 7000 feet. Chance of precipitation is 25%. Partly cloudy then becoming sunny.
Temperatures: 10 to 18. deg. F. 1 below to 4 above zero. deg. F. 21 to 26. deg. F.
Mid Slope Winds: Southwest 15 to 25 mph. Gusts up to 55 mph decreasing to 45 mph in the afternoon. West 10 to 15 mph with gusts to 30 mph. Northwest 15 to 20 mph. Gusts up to 30 mph increasing to 45 mph in the afternoon.
Expected snowfall: 80% probability of 3 to 9 inches. 20% probability of 9 to 12 inches. | SWE = up to 0.45 inch. in. 30% probability up to 1 inch. 70% probability up to 2 inches. | SWE = less than 0.10 inch. in. None in.
Over 10,000 ft.
Tuesday Tuesday Night Wednesday
Weather: Cloudy. Snow showers. Snow levels below 7000 feet. Chance of precipitation is 100%. Mostly cloudy then becoming partly cloudy. Chance of snow showers in the evening. Snow levels below 7000 feet. Chance of precipitation is 30%. Partly cloudy then becoming sunny.
Temperatures: 4 to 10. deg. F. 1 below to 6 below zero. deg. F. 17 to 22. deg. F.
Ridge Top Winds: Southwest 30 to 45 mph with gusts to 75 mph decreasing to 20 to 30 mph with gusts to 55 mph in the afternoon. West 15 to 25 mph with gusts to 35 mph. Northwest 15 to 30 mph. Gusts up to 35 mph increasing to 45 mph in the afternoon.
Expected snowfall: 80% probability of 4 to 8 inches. 20% probability of 9 to 15 inches. | SWE = up to 0.50 inch. in. 30% probability up to 1 inch. 70% probability of 2 to 3 inches. | SWE = less than 0.10 inch. in. None 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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