Avalanche Advisory: Thursday - Mar 12, 2020 | Eastern Sierra Avalanche Center

THIS AVALANCHE ADVISORY EXPIRED ON March 13, 2020 @ 6:53 am
Avalanche Advisory published on March 12, 2020 @ 6:53 am

Issued by Chris Engelhardt - Eastern Sierra Avalanche Center

Bottom Line

LOW avalanche danger exists at all elevations Thursday. Be on the lookout for isolated wind slabs that may be possible on ALL aspects at Upper Elevations. NE winds will increase today and redistribute and cross-load recent low density snow in complex and extreme alpine terrain, such as couloirs and slopes adjacent to cliff bands and rock outcroppings.

1. Low

Above Treeline

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

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.

Avalanche Problem 1: Wind Slab

Type ?
Aspect/Elevation ?
Likelihood ?

Certain

Very Likely

Likely

Possible

Unlikely
Size ?

Historic

Very Large

Large

Small

Continue to monitor for pockets of unstable, shallow wind slab on isolated terrain features. Field observations in the upper elevations yesterday found from 1-3” of new snow with drifts up to 5” from the Tuesday/Wednesday little storm. There were also residual amounts of loose surface snow remaining from last Saturday’s snowfall and in combination makes for decent amounts of snow available for transport. NE winds will pick up a bit today and re-distribute snow to a variety of aspects. Although any wind slab avalanche likely will be small, if it occurs in exposed or confined terrain it could prove to be consequential for a rider getting pushed off their feet. Look for recent loose snow avalanche activity and fresh cross loaded ribbons and pillows of snow established on terrain features conducive to capturing snow. Be observant of overhead hazards, and plan your route accordingly if you’re travelling in tight and confined terrain where small slides and spindrift originating in the alpine could funnel snow in your direction. Look for blowing snow and anticipate that warming from the sun could loosen freshly deposited small panels of snow from sunny aspects today. Side walls of couloirs, gullies, and terrain adjacent to rock bands and collection zones will most likely hold pockets of newly transported snow.

Avalanche Problem 2: Loose Wet

Type ?
Aspect/Elevation ?
Likelihood ?

Certain

Very Likely

Likely

Possible

Unlikely
Size ?

Historic

Very Large

Large

Small

With partly cloudy conditions, warm overall temperatures and NE winds transporting snow to Sunny aspects, pay attention for small loose wet activity on E-SE-S-SW-W aspects today. New point release activity, fresh Roller balls and pin-wheeling of snow are all indicators of warming and loosening of the residing snow. Pay particular attention if you’re attempting routes that are affected from terrain above that is getting significantly warmed from the sun. Be observant for even small amounts of moving snow or rock fall that could impact you from above, especially if in tight or confined terrain that is exposed to overhead hazards.

advisory discussion

Yesterday’s small refresher made for good riding conditions and with some loading winds, skiing conditions have improved mid-week. Simple fact though is that the thin and obstacle ridden baseline conditions have been a concern all season. With shallow reefs, firm wind shorn surfaces, and newly disguised rock, continue to remind yourself that this has not been the season to ski with abandon in the backcountry.

recent observations

Submit Snowpack Observations

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3/11- Mammoth Area –Mammoth Crest/Hammil Bowl–snow conditions

3/11 – June Lake Area –New snow in Negatives- snow conditions

3/10- Mammoth Area –Sherwins- snow conditions

3/10 – Virginia Lakes – Snow conditions

Weather and CURRENT CONDITIONS

weather summary

Partly cloudy conditions will prevail today with moderate NE winds (15-25mph) and gusts of up to 35mph at ridge top. Temperatures could reach 50F for the lower mountain elevations, while 29-39F is slated above 10000ft. Warm temperatures and mild weather will continue until this weekend when a strong storm hits the region with high winds and potential significant snowfall through Monday for the Sierra Crest.

Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS

For 8,000 ft. to 10,000 ft.

	Thursday	Thursday Night	Friday
Weather:	Partly cloudy. Snow levels 8000 feet. Chance of precipitation is 5%.	Clear. Snow levels 8000 feet decreasing to below 7000 feet after midnight. Chance of precipitation is 0%.	Sunny. Snow levels below 7000 feet increasing to 8000 feet in the afternoon. Chance of precipitation is 5%.
Temperatures:	40 to 50. deg. F.	23 to 29. deg. F.	42 to 52. deg. F.
Mid Slope Winds:	Northeast around 15 mph with gusts to 30 mph.	North around 15 mph with gusts to 30 mph in the evening becoming light.	Light winds becoming west around 15 mph with gusts to 30 mph in the afternoon.
Expected snowfall:	0 in.	0 in.	0 in.

Over 10,000 ft.

	Thursday	Thursday Night	Friday
Weather:	Mostly cloudy then becoming partly cloudy. Snow levels 8000 feet. Chance of precipitation is 5%.	Partly cloudy then becoming clear. Snow levels 8000 feet decreasing to 7000 feet after midnight. Chance of precipitation is 0%.	Sunny. Snow levels below 7000 feet increasing to 8000 feet in the afternoon. Chance of precipitation is 5%.
Temperatures:	29 to 39. deg. F.	16 to 22. deg. F.	32 to 40. deg. F.
Ridge Top Winds:	Northeast 15 to 25 mph with gusts to 35 mph.	North 15 to 20 mph with gusts to 30 mph.	West 15 to 20 mph. Gusts up to 30 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.