Eastern Sierra Backcountry Snow Report – March 10th, 2017

In Conditions Reports, Eastern Sierra Backcountry Snow Report, From the Range of Light & Fast by Howie SchwartzLeave a Comment

Hi backcountry skiers and snowboard riders,

We meet again! We have neglected this report for a month and a half now. If this has pissed you off… then good. I guess we are doing it well, when we do it. But anyone who actually has been skiing in the Eastern Sierra since we last reported knows that really there has been little to report, other than that this amazing winter got even better through late February. If this is news to you, check the photos here to see what you have missed.

As we near the end of winter 2016-17, we should reflect and consider that it has been one of the greatest winters on record. That isn’t being hyperbolic, or trying to sell more guided trips (our ski guide staff is nearly maxed through at least April). What you need to know is that Mammoth Mountain has received over 40 feet of snow, as measured at the 9000 foot level. Now that last part is pretty important because nearly all of the big storms of the season so far have been atmospheric rivers, very wet and warm storms from the tropics that has had their focus of energy pointed right at the Sierra. The amount of precipitation that fell as rain at 9000′ was not insignificant this year. Imagine how much snow is on the slopes at 10,000+ feet, or in the deposit zones of the avalanches that have been triggered all season.

But the story of one of the greatest winters on record does not end with simply the amount of snow and the high frequency of storms. By some miracle of nature, nearly all of the storms finished cold and without windy days following. This is a rare scenario in winter in the Sierra. We were skiing moderately deep powder the likes of which is typically found in places like Utah and Alaska, but top to bottom from 14,000′ down to as low as ~5000′. Yes, you heard that right. Up to 9000′ of real powder skiing from alpine summits into the desert.

The last 6 weeks have seen direct action snow instability with very large to historic scale natural avalanches triggered from heavy loading events that included some rain on snow. There are many places with 20+ foot piles of debris amidst the desert sagebrush. Generally stable snow conditions have existed in the good weather periods between storms. This can change quickly due to new precipitation, wind, sun, and warm temperatures so be sure to check the Eastern Sierra Avalanche Center for the latest advisory, now being published at 7am, 5 days/week! Submit your observations to them and give them your support for the benefit of all of us.

When we talk about the “greatest winter” we have to be sensitive to the fact that Mammoth Lakes residents are mostly over it. Shoveling can cause debilitating chronic injuries. Roofs collapse. Supposedly the math works out that a 10 meter x 10 meter house with 2 meters of snow on it at 30% avg. density has 132,000 pounds (66 tons) weighing on it. There is such thing as too much of a good thing. I imagine some of us up there are in dire situations and could use community support.

Where are we now? The last couple weeks have seen continued AR storms followed by strong winds. We lost a ton of snow down low to February rain up to 7500′. Recent winds have stripped snow up high. But in the middle, we have a ton of snow and epic coverage. In the last week, spring has sprung. Bishop had a high of 75 degrees today. The last storm that produced deep snow up North in Tahoe, was about 10-12 inches in Mammoth and barely touched the Southern part of the range. The snow surface is a very mixed bag as a result. One can find some powder in the steep and shaded forests. the open terrain has a mix of: almost ankle deep facet powder in the most sheltered shaded  places, supportable, bulletproof, and breakable wind crusts, wonderful spring snow, and some transitional not-yet-wonderful spring snow.

The best of these is clearly the spring snow, which can be found typically below 11-12,000′ feet on steeper slopes that face SW-S-SE, especially near rocks and other radiation emitters/reflectors. It is important to get an early start on warm, calm days in these conditions. It is suddenly March and the sun is getting stronger. When chasing corn, get your act together, plan accordingly, and don’t be afraid to start in the dark. It is all about energy balance at the snow surface. We need freezing solid at night, followed by the right amount of melt in the day. Solar radiation will be offset easily this time of year by clouds and wind so it has to be a splitter day right now. Variability and firmness in many areas means that the skinning is rugged. Not for the meek or uninitiated. Ski/boot crampons and ice axes are advised for many itineraries at this time.

If planning High Sierra spring tours (and if not, you should!), realize that it could be a long and fruitful season. Many study sites in the Southern part of the range are now measuring above 200% of the April 1 average, and some are above 250%. Extraordinary. Enjoy it out there and be safe. If you want more frequent, real-time insights into how conditions are doing, follow us on Facebook and Instagram.

Highlights since last report:


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