Avalanche Advisory: Tuesday - Jan 14, 2020 | Eastern Sierra Avalanche Center

Avalanche Problem 1: Wind Slab

Type ?
Aspect/Elevation ?
Likelihood ?

Certain

Very Likely

Likely

Possible

Unlikely
Size ?

Historic

Very Large

Large

Small

Shallow, fresh wind deposits could exist on N-E aspects, particularly in catchment zones where extreme and erratic winds may have laid down eroded snow on a variety of terrain features. Also remain on the lookout for enduring stubborn wind slabs in isolated areas of complex terrain. Be particularly aware of unsupported slopes, convex rolls, or if you’re traveling in tight confined terrain (couloirs) where you are exposed from hazards above. Areas adjacent to cliffs, outcroppings, or cross-loaded gullies may have the greatest potential for new wind slab development.

advisory discussion

Riding has become limited with challenging snow surfaces and the lack of fresh snow. Most exposed terrain consists of firm, smooth wind board, breakable crust and both soft and hardened sastrugi. “Slide for life” conditions, thin snow cover and potential for hitting obstacles are the biggest hazards right now. The snowpack is extremely variable both in depth and structure across the forecast zone, so every drainage and mountain should be assessed for what is going on in your specific area. Violent winds will continue to impact the mountains Tuesday making for unpleasant conditions. These SW winds combined with slight chance of snow flurries could produce erratic loading patterns and potential releasing of panels of snow or spindrift in complex terrain. Be particularly aware if you’re travelling in gullies or chutes that can funnel cascading snow.

recent observations

Submit Snowpack Observations

Submit Avalanche Observations

1/13 - Big Pine - snow conditions

1/12 – Bishop Area – Basin Mountain – thin conditions, shooting cracks and collapsing

1/12 –June Lake Area – White Wing & Glass Creek – snow conditions

1/11 – Mammoth Area – Sherwins– wind effects

1/10 – Mammoth Area –Mammoth Crest - Snow Conditions

Weather and CURRENT CONDITIONS

weather summary

Strong to Extreme W-SW winds will rake the range today with minimal chances of snow this morning. 100mph gusts and 50-70mph average velocities are slated to start the day and gradually decrease by the afternoon. Partly cloudy conditions will exist with cooler temperatures of 18-26F in the upper elevations and reaching the mid 30sF in the lower regions. Prepare accordingly for nippy wind chill factors. Forecasts are still targeting Wednesday night/Thursday as the large producer for significant snow totals: 8-16” in Mono county with possibly up to 24” on the Sierra Crest.

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. Chance of snow in the morning. Snow levels below 7000 feet. Chance of precipitation is 20%.	Clear then becoming partly cloudy. Snow levels below 7000 feet. Chance of precipitation is 5%.	Partly cloudy. Snow levels below 7000 feet. Chance of precipitation is 5%.
Temperatures:	25 to 35. deg. F.	14 to 20. deg. F.	32 to 40. deg. F.
Mid Slope Winds:	Southwest 30 to 45 mph decreasing to 25 to 35 mph in the afternoon. Gusts up to 85 mph.	Southwest 15 to 25 mph. Gusts up to 50 mph decreasing to 40 mph after midnight.	Southwest around 15 mph. Gusts up to 35 mph increasing to 50 mph in the afternoon.
Expected snowfall:	30% probability up to 2 inches. 70% probability no accumulation. \| SWE = less than 0.10 inch. in.	0 in.	0 in.

Over 10,000 ft.

	Tuesday	Tuesday Night	Wednesday
Weather:	Partly cloudy. Chance of snow in the morning. Snow levels below 7000 feet. Chance of precipitation is 30%.	Clear. Snow levels below 7000 feet. Chance of precipitation is 5%.	Sunny then becoming partly cloudy. Snow levels below 7000 feet. Chance of precipitation is 5%.
Temperatures:	18 to 26. deg. F.	9 to 14. deg. F.	24 to 32. deg. F.
Ridge Top Winds:	Southwest 50 to 70 mph decreasing to 40 to 60 mph in the afternoon. Gusts up to 100 mph.	West 20 to 30 mph with gusts to 50 mph.	Southwest 20 to 35 mph. Gusts up to 45 mph increasing to 60 mph in the afternoon.
Expected snowfall:	40% probability up to 2 inches. 60% probability no accumulation. \| SWE = less than 0.10 inch. 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.