Avalanche Advisory: Saturday - Nov 30, 2019 | Page 2

THIS AVALANCHE ADVISORY EXPIRED ON December 1, 2019 @ 7:00 am
Avalanche Advisory published on November 30, 2019 @ 7:00 am

Issued by Josh Feinberg - Eastern Sierra Avalanche Center

Bottom Line

How to read the advisory

This will be the final season update before regularly scheduled advisories begin on Monday Dec 2nd.

2-5 feet plus of new light snow has fallen between Tuesday afternoon and Friday, with winds varying between strong and light. Wind slabs with lingering sensitivity in exposed areas will be the greatest avalanche concern for Saturday before another significant storm moves in Saturday evening thru Monday morning spiking avalanche danger. Prior to this Thanksgiving storm a very thin snowpack existed, if any at all. Beware of the invisible rocks and logs lurching below the surface of this new light snow!

No Rating

Above Treeline

No Rating

Near Treeline

No Rating

Below Treeline

advisory discussion

It was a dry fall for the mountains of the Eastern Sierra. Slopes remained essentially bare up to November 20-21, when the first small storm of the season hit dropping up to a few inches of snow in the high country. Click here for a picture of McGee Mtn prior to Thanksgiving.

Then Thanksgiving arrived with the first real storm of the season transforming the mountains into a winter wonderland. This cold storm had snow levels reaching all the way down to 2000’, and 2-5ft plus of snow above 8000’. For those hardy souls chomping at the bit to finally get skis on their feet it was trench warfare breaking trail, with ski penetration up to waist deep. This arduous trail breaking and the stormy conditions kept most out of harms way in terms of avalanches, but Mammoth Mountain Ski Patrol reported quite active avalanche conditions on Friday with crowns ranging between 1 to 4 feet, mostly in the form of wind slabs.

Wind slabs with lingering sensitivity will be the greatest avalanche concern for Saturday. Keep an eye out for denser, wind deposited snow below ridgetops and across slopes where terrain promotes drifting. Do your own localized assessements before travelling across steep potentially wind loaded slopes, and when in doubt avoid them. Refresh yourself on safe travel protocols: one at a time in steep terrain, keep an eye on your partner, and of course always carry your beacon, shovel and probe.

Don't let the allure of these fresh snow-covered slopes fool you, not far under the surface lie a plethora of sharks and landmines in the form of rocks and logs. Already one skier reported smacking a log with his shins, luckily he wasn’t moving too fast and wasn’t hurt badly. Take it slow, let this next storm add to the base before even thinking about opening it up!

Deep snow emersion is a real threat as well! Falling head first in the snow, especially in a tree well, could have grave consequence.

And finally, if you get out into the mountains, please let us know what you see out there thru our observation page! The more we hear from you, the better our forecasts can be.

recent observations

Submit Snowpack Observations

Submit Avalanche Observations

-11/30 - Mammoth Rock - Sherwins: Conditions

-11/30 - Mammoth Rock - Sherwins: Snowpack

-11/30 - Convict: Snowpack

Weather and CURRENT CONDITIONS

weather summary

For Saturday expect mostly cloudy skies and light winds before snowfall begins this afternoon and evening.

A Winter Storm Warning is in effect beginning late day Saturday thru Monday mid morning. 2-5 feet of new snow is expected during this time, with greatest intensities throughout the day on Sunday. Snowlines will be mostly around 7000ft rising up to around 8000ft Monday morning. This storm appears to be much less windy than the last staying in the moderate range at mid to upper elevations out of the south and southwest.

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

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

	Saturday	Saturday Night	Sunday
Weather:	Mostly cloudy. Chance of snow in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 25%.	Cloudy. Chance of snow in the evening, then snow after midnight. Snow levels below 7000 feet. Chance of precipitation is 75%.	Cloudy. Snow. Snow levels below 7000 feet increasing to 7000 feet in the afternoon. Chance of precipitation is 90%.
Temperatures:	24 to 29. deg. F.	20 to 25. deg. F.	27 to 32. deg. F.
Mid Slope Winds:	South around 15 mph. Gusts up to 25 mph in the afternoon.	South 15 to 25 mph. Gusts up to 30 mph increasing to 45 mph after midnight.	South 15 to 25 mph with gusts to 40 mph.
Expected snowfall:	up to an inch late in the day. \| SWE = less than 0.10 inch. in.	80% probability of 2 to 4 inches. 20% probability of 4 to 6 inches. \| SWE = 0.20-0.45 inch. in.	80% probability of 6 to 10 inches. 20% probability of 10 to 15 inches. \| SWE = 0.60-1.10 inches. in.

Over 10,000 ft.

	Saturday	Saturday Night	Sunday
Weather:	Mostly cloudy. Chance of snow in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 30%.	Cloudy. Snow likely in the evening, then snow after midnight. Snow levels below 7000 feet. Chance of precipitation is 85%.	Cloudy. Snow. Snow levels 7000 feet. Chance of precipitation is 95%.
Temperatures:	22 to 27. deg. F.	18 to 23. deg. F.	23 to 28. deg. F.
Ridge Top Winds:	Southwest 15 to 20 mph increasing to 15 to 30 mph in the afternoon.	South 20 to 35 mph. Gusts up to 50 mph after midnight.	South 25 to 35 mph with gusts to 45 mph.
Expected snowfall:	No accumulation. 70% probability no accumulation. \| SWE = less than 0.10 inch. in.	80% probability of 3 to 6 inches. 20% probability of 6 to 10 inches. \| SWE = 0.25-0.50 inch. in.	80% probability of 6 to 10 inches. 20% probability of 10 to 15 inches. \| SWE = 0.65-1.10 inches. 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.