Avalanche Advisory: Tuesday - Mar 12, 2019 | Eastern Sierra Avalanche Center

THIS AVALANCHE ADVISORY EXPIRED ON March 13, 2019 @ 6:38 am
Avalanche Advisory published on March 12, 2019 @ 6:38 am

Issued by Josh Feinberg - Eastern Sierra Avalanche Center

Bottom Line

As winds increase and shift, avalanche danger is MODERATE at upper elevations due to fresh sensitive and older more stubborn wind slabs. While avalanche danger is LOW at mid and low elevations, sunshine and slightly warmer temperatures could lead to some minor loose-wet activity on sunny aspects. Human triggered avalanches are possible.

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

NE ridge-top winds spiked overnight and will gradually increase again thru today even at mid-elevations while shifting out of the SW and W. Gusts are expected into the 50s and 60s by this afternoon. Loose snow in exposed areas from last week’s storm is dwindling, but there is still enough to be transported into small sensitive wind slabs. With the shifting winds, fresh sensitive and older more stubborn wind slabs could be found on any aspect at upper elevations, and potentially into mid elevations as well. Look for these just below ridgelines, sidewalls of gullies, and in across-slope deposition zones. Do your own localized assessments of denser wind-deposited snow, and be weary that triggering even a small pocket could lead to a nasty fall in steep consequential terrain.

Avalanche Problem 2: Loose Wet

Type ?
Aspect/Elevation ?
Likelihood ?

Certain

Very Likely

Likely

Possible

Unlikely
Size ?

Historic

Very Large

Large

Small

Sunny skies today, and slightly warmer temperatures reaching the mid-30s at lower elevations could lead to some loose-wet activity on sun-exposed slopes at low to mid elevations. While this is likely to remain minor, larger rollerballs and sinking deeper into wet snow are signs that larger loose-wet avalanches may be possible and to seek shadier slopes. Keep in mind how warming rock bands might be loosening snow above you as well. Increasing SW winds cooling slopes this afternoon will decrease this concern.

recent observations

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-3/11 - Mammoth - Hemlock above Sotcher Lake: NE winds transporting snow, propogating test results on facets above melt-freeze crust.

-3/11 - Bishop Creek - Jawbone Canyon: 6" of new light snow, minor shooting cracks, small loose-wet point releases.

-3/11 - Mammoth - Sherwins/Mammoth Rock Bowl: Tests and conditions

-3/11 - Mammoth - Sherwins: NE winds at ridgetop.

Weather and CURRENT CONDITIONS

weather summary

Expect sunny skies today with increasing winds and a chance of snow showers this afternoon and tonight as a fast moving cold front moves thru the area. Winds will shift back out of the SW and W, gusting into the 60s over ridge-tops by this afternoon. No accumulation of new snow expected today, and perhaps up to an inch tonight. High temperatures should reach ~30° around 10,000’ at noon before cooling down into the single digits tonight.

High pressure will begin building on Wednesday bringing gradually warming temperatures and keeping conditions dry thru at least early next week until a more active storm pattern may return.

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:	Sunny. Chance of snow in the afternoon. Chance of precipitation is 20%.	Partly cloudy. Chance of snow in the evening, then slight chance of snow showers after midnight. Chance of precipitation is 35%.	Sunny.
Temperatures:	31 to 39. deg. F.	8 to 14. deg. F.	24 to 32. deg. F.
Mid Slope Winds:	Light winds becoming southwest 15 to 20 mph with gusts to 50 mph in the afternoon.	Northwest 15 to 25 mph. Gusts up to 50 mph decreasing to 40 mph after midnight.	North around 15 mph with gusts to 45 mph.
Expected snowfall:	trace in.	Up to 1 inch. \| SWE = less than 0.10 inch. in.	0 in.

Over 10,000 ft.

	Tuesday	Tuesday Night	Wednesday
Weather:	Mostly sunny. Slight chance of snow in the afternoon. Chance of precipitation is 20%.	Partly cloudy. Chance of snow in the evening, then slight chance of snow showers after midnight. Chance of precipitation is 35%.	Sunny.
Temperatures:	24 to 30. deg. F.	4 to 9. deg. F.	18 to 24. deg. F.
Ridge Top Winds:	Southwest around 15 mph with gusts to 30 mph increasing to west 25 to 35 mph with gusts to 60 mph in the afternoon.	Northwest 25 to 40 mph with gusts to 60 mph decreasing to 20 to 30 mph with gusts to 45 mph after midnight.	North 20 to 35 mph. Gusts up to 45 mph increasing to 55 mph in the afternoon.
Expected snowfall:	trace in.	Up to 1 inch. \| SWE = less than 0.10 inch. 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.