Fwd: Donner Summit Snow Report 2019-03

[Paul Minault]

FYI

-------- Forwarded Message --------

Subject:	Donner Summit Snow Report 2019-03
Date:	Fri, 18 Jan 2019 06:04:10 +0000 (UTC)
From:	Richard Simpson <hut....@yahoo.com>
To:	hut....@yahoo.com <hut....@yahoo.com>

This report usually goes to about 45 people in the Sierra Club Loma Prieta Chapter Ski Touring Section.  For this week I am adding members of a group contemplating a tour in Carpenter Valley organized by the Truckee Donner Land Trust and participants in my trip to Peter Grubb Hut on the weekend of January 26-27.

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We left Donner Summit on January 7 with my deck at Serene Lakes (7000 ft) clear.  When we returned yesterday about 5 PM, there was 2-3 feet of snow on the deck and a new storm starting.  Since then, there have been only a few moments when snow was not falling; we have probably accumulated 2-3 feet of additional snow since 5 PM yesterday.  The forecast has 3-5 inches more tonight, then a couple days with little or no precipitation.

The snow in the past 30 hours has fallen while the temperature held at 30±2 degrees.  So it is 'wet' and dense without being sticky.  Total depth in the woods is now 6-8 feet; the attached photo shows a marker I placed on a tree in March 2017, when we had near record snow.  We're less than 6 feet from that peak depth and it's only mid-January.

I skied in the woods for about an hour late this afternoon.  I climbed to the summit of a nearby knob (7373 ft) and had very little trouble breaking trail.  The heavy snow apparently is self-compacting.  My backcountry skis only sank about an inch on most surfaces; the pattern on the ski bottoms was good enough for climbing, and I had a nice telemark run down an untracked slope on the way home.  I did not take my dog on this tour, fearing his paws would break through; Chaco gets to try the new snow tomorrow.

Royal Gorge did not open today because of white-out conditions and buried grooming machines; they predict a late start tomorrow.  Sugar Bowl started Thursday with several lifts running, but had only one lift going at the end of the day (because of wind); their web site promises overnight work to be ready for Friday.

With this new snow come some hazards.  The base at the end of December was rock hard; the snow that fell next was very dry and fluffy; more recently it has been heavy and wet.  Although there has been consolidation and bonding, there are clear layers.  I found one boundary about 12 inches down with my ski poles this afternoon.  The Sierra Avalanche Center (https://www.sierraavalanchecenter.org) rated avalanche danger "4.High" at all elevations today (Thursday).  "Very dangerous and complex avalanche conditions continue due to a mix of wind slabs, storm slabs, and deep persistent slabs."  Travelers in or near avalanche zones should be very careful.

There is another hazard.  The snow that fell yesterday was wet and clung to tree branches.  As the temperature fell last night, those 'snow bombs' glued themselves to the trees; almost all of them are still there.  On my tour this afternoon I was hit by some small pieces when a wind gust came through; it was enough to rattle my teeth.  The larger bombs could cause real injury once temperatures reach the mid-30s.  Avoid skiing under trees when you can; be alert to to the hazards overhead when you can't.

With relative clearing tomorrow, road crews should be able to catch up on plowing.  As of this writing (Thursday 10 PM), chain requirements are in effect on I-80 between Baxter and the Nevada line.  Chains are also required on CA 89 north and south of Truckee.  Donner Pass Road is open (chains required) from Soda Springs to the Summit; from the Summit to Donner Lake is closed until Friday morning.  Lesser used roads are in various stages of plowing; many infrequently used roads have been reduced to one lane until blowers clear side berms.  Condition of parking lots is unknown.

The forecast for Friday-Saturday is cloudy with snow showers.  There should be good skiing at resorts once parking has been cleared and avalanche dangers addressed; but expect congestion, especially Saturday.  High temperatures at 7000 ft should hover just below freezing Friday, then rise to the mid 30s Saturday, possibly making snow sticky (and releasing snow bombs).  Without sun, there should be no serious ice developing on snow surfaces overnight.  Sunday another 8-12 inches of snow is forecast for 7000 ft; in Truckee, it will start as rain, then change to 1-3 inches of snow.  Monday is forecast to be mostly sunny but cold (high 27F at 7000 ft) — possibly the best ski day of the weekend.  Those contemplating Carpenter Valley should bring shovels in case parking needs to be cleared, but the snow coverage on the tour, the ski conditions, and the weather all look generally good.

Next week should be mostly clear and sunny with high temperatures around 40F.  That makes all of the new snow this weekend pretty 'old' and crusty by January 26-27.  However, north facing slopes could still hold powder and avalanche danger should drop.  

We've finally got a winter like they used to be; be careful, but enjoy.