Avalanche Advisory: Tuesday - Dec 31, 2019 | Eastern Sierra Avalanche Center

THIS AVALANCHE ADVISORY EXPIRED ON January 1, 2020 @ 6:23 am
Avalanche Advisory published on December 31, 2019 @ 6:23 am

Issued by Chris Engelhardt - Eastern Sierra Avalanche Center

Bottom Line

How to read the advisory

MODERATE avalanche danger exists at Upper elevations on all Aspects for Wind Slab hazard. LOW avalanche danger exists at mid to lower elevations. Remain vigilant in carefully evaluating snow and terrain.

2. Moderate

Above Treeline

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

1. Low

Near Treeline

Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

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

Continue to evaluate and perform your own local assessments on All Aspects if venturing into steep terrain with features that capture drifting snow. The intricacies of the alpine environment in relation to subtle aspect change or the way it affects wind direction can be very specific to your individual run choice. Although transportable snow up high is waning there were some minor accumulations yesterday, so look out for actively blowing snow and deposition vs scoured snow surfaces. Moderate northerly winds up high today combined with solar input and warmer temps may cut something loose from sunnier aspects that could steamroll you way below…especially if you’re in areas that entrain or gather sliding snow. Human triggered avalanches are possible, so continue to identify features of concern and plan accordingly.

advisory discussion

As the New Year approaches, overall weather patterns look to be stalling for our forecast zone with a period of drier conditions. 2019 has produced pretty darn good riding, yet the northern and southern end of the forecast zone is still relatively shallow compared to the Mammoth area. There have been lots of reports of near misses and injuries from hitting obstacles across the zone. Unfortunately there was not another “lake effect” precipitation event yesterday in the June Lake area, but it certainly was a welcome surprise and present that hit that area Christmas night. There are definitely reservoirs of snow ready to be mined by the winds so per normal…extra vigilance should be taken in tight, convex, or exposed terrain.

HAPPY NEW YEAR and THANKS to all who have been submitting reports, they’re invaluable to keeping the knowledge rolling and current!!!

recent observations

Submit Snowpack Observations

Submit Avalanche Observations

12/30 – June Lake Area– Hemlock Ridge – Snow Conditions

12/30 – Mammoth Area- Panorama Dome/Mill City area –snow depths & conditions

12/30 – Lee Vining –V Bowl & Bishop Area –Pine Creek –current coverage update

12/29 – Mammoth Area – Mammoth Rock – Small Skier triggered avalanche

12/29 – Mammoth Area – Mammoth Rock Bowl– Crevasse at top of Mammoth Rock Bowl

12/28 – Convict Area– Mono Jim Peak – Skier triggered avalanche

Weather and CURRENT CONDITIONS

weather summary

A sunny to partly cloudy day is on tap with light winds for the last day of 2019. Moderate northeasterly winds will continue to blow up high and temperatures should be mild (26-32F) above 10000ft. The mountains could possibly see a bit of snow New Year’s Day as a quick hitting storm pushes through the area.

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:	Partly cloudy	Clear then becoming partly cloudy	Partly cloudy then becoming mostly cloudy
Temperatures:	31 to 37 deg. F.	22 to 27 deg. F.	35 to 43 deg. F.
Mid Slope Winds:	Light winds	Light winds	Northwest 15 to 20 mph. Gusts up to 40 mph increasing to 60 mph in the afternoon
Expected snowfall:	0 in.	0 in.	0 in.

Over 10,000 ft.

	Tuesday	Tuesday Night	Wednesday
Weather:	Sunny then becoming partly cloudy	Clear then becoming partly cloudy	Partly cloudy then becoming mostly cloudy
Temperatures:	26 to 32 deg. F.	18 to 23 deg. F.	29 to 35 deg. F.
Ridge Top Winds:	Northeast 15 to 20 mph with gusts to 35 mph	North 15 to 30 mph with gusts to 45 mph	West 15 to 30 mph with gusts to 50 mph increasing to northwest 30 to 45 mph with gusts to 75 mph in the afternoon.
Expected snowfall:	0 in.	0 in.	0 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.