Avalanche Advisory: Monday - Mar 25, 2019

THIS AVALANCHE ADVISORY EXPIRED ON March 26, 2019 @ 6:40 am
Avalanche Advisory published on March 25, 2019 @ 6:40 am
Issued by Chris Engelhardt - Eastern Sierra Avalanche Center

The avalanche danger will be MODERATE at Upper and Middle elevations today. Wind slab avalanches on N-E aspects are the chief concern primarily in the northern part of the forecast zone. Avalanche danger remains less concerning in the southern end of the forecast zone where much less snow fell over the weekend.

2. Moderate

?

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

2. Moderate

?

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

1. Low

?

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
  • Type ?
  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

Be on the lookout for fresh and sensitive wind slab primarily on NORTHERLY-EASTERLY slopes today.  Estimated amounts of 3-6” of new snow fell Saturday (mostly from Mammoth Lakes to the North) and SOUTHERLY winds have been actively loading transportable snow to leeward slopes. Optimal loading winds will continue today coupled with extreme gusts that could load snow on a variety of aspects, both at high and mid elevations. Pay attention for actively transporting snow, firm harder slab residing above softer weak snow, freshly formed cornices, and red flags such as shooting cracks, drummy, hollow sounding snow, and recent natural avalanche activity. There has been numerous reported skier triggered and natural wind slab avalanches over the weekend. Most have been shallow in depth and width, but have been large enough to carry a person down slope and even bury them in some cases (D2 scale). These reported slides have been reported on not only northerly aspects, but also on SE aspects. CORNICE FAILURE has also been reported as a driving force in some observed avalanches.

Avalanche Problem 2: Cornice
  • Type ?
  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

Avoid CORNICES particularly on EASTERLY aspects. Cornice fall not only is hazardous if it gives way beneath you, but can affect travelers on slopes below. Pay specific attention to overhead hazards if your ski objective requires you to ascend slopes or coloirs below hanging cornices. Think twice before spending time exposed to freshly formed overhead cornices. Cornice fall can be the big trigger that starts avalanches on slopes below as the falling blocks can be of tremendous weight and scale. Give these curling wavelike features a wide berth and make sure you are well on terra firma if travelling on top of ridges where cornices reside. 

Avalanche Problem 3: Loose Wet
  • Type ?
  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

Partly cloudy to sunny skies are expected today. Continued warm temperatures will primarily loosen snow on SOLAR ASPECTS. Be particularly aware of unsupportable snow (take off your ski/board and check for boot penetration), and active shedding of snow surfaces such as pinwheeling and roller balls. SOUTHERLY aspects in confined terrain such as couloirs or other constricted features will be of most concern, but pay attention to all aspects as potential cloud cover may change heating effects today. Resulting avalanches may be small, but could entrain enough heavy saturated snow to make for a nasty ride if caught.

Weather and CURRENT CONDITIONS
weather summary

Southerly winds are predicted to ramp up today for the region with gusts climbing to 70-80mph and overall strong to extreme velocities for the mid to higher elevations. Partly cloudy to sunny skies will preside over the area with warmer spring like temperatures. Above freezing temperatures are forecast for mid to lower elevation bands today (35-45F). Things will stay relatively cool above 10000ft today (24-32F).

Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 8,000 ft. to 10,000 ft.
Monday Monday Night Tuesday
Weather: Partly cloudy. Partly cloudy. Mostly cloudy. Chance of snow. Chance of precipitation is 40%.
Temperatures: 35 to 45. deg. F. 23 to 29. deg. F. 30 to 40. deg. F.
Mid Slope Winds: South 15 to 25 mph increasing to 25 to 35 mph in the afternoon. Gusts up to 70 mph. Southwest 15 to 30 mph with gusts to 75 mph. Southwest 15 to 30 mph increasing to 25 to 35 mph in the afternoon. Gusts up to 60 mph.
Expected snowfall: 0 in. 0 in. 2 in.
Over 10,000 ft.
Monday Monday Night Tuesday
Weather: Partly cloudy. Snow levels below 7000 feet. Chance of precipitation is 0%. Partly cloudy then becoming mostly cloudy. Snow levels below 7000 feet. Chance of precipitation is 10%. Mostly cloudy. Chance of snow through the day. Snow levels below 7000 feet. Chance of precipitation is 50%.
Temperatures: 24 to 32. deg. F. 17 to 22. deg. F. 24 to 32. deg. F.
Ridge Top Winds: Southwest 30 to 50 mph with gusts to 80 mph. Southwest 35 to 55 mph with gusts to 80 mph. Southwest 30 to 50 mph with gusts to 70 mph.
Expected snowfall: 0 in. 0 in. 2 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.

ESAC receives support from ...