The Crested Butte Avalanche Center has ended daily operations for the winter of 2017-18, but we will provide routine conditions updates through April 15th. Please do submit your backcountry observations and we'll keep the community abreast of significant avalanche events. Thank you!!!
A biting cold front poured over the mountains Thursday night into Friday. Storm totals range from 6 to 8 inches in near Paradise Divide, tapering down to a skiff in town.
This new snow falls on stiff old snow surfaces, so expect this new snow to slough on steep slopes over 40 degrees. Loose Dry avalanches are possible Saturday, transitioning to Loose Wet avalanches on sunny slopes on Sunday once temperatures nose above freezing in the afternoon.
With Friday night and Saturday's strong north to northwest flow, this weekend you'll find isolated drifts up to 2 feet near ridge crests on East to Southeast slopes. You could trigger small Wind Slab avalanches this weekend, at least until our next warm up, coming Monday.
The Persistent Slab problem hasn't gone away completely, though it's restricted to alpine terrain on North to East aspects. Recent warm weather formed very strong ice lenses in the upper snowpack on most other slopes, now frozen solid. Until our next warm up, it's unlikely you'll trigger any Persistent Slab avalanches.
As you look at the mountains surrounding Crested Butte it's not hard to recognize the current conditions are not your typical mid-April conditions. Spring sprang surprisingly sloppily Saturday. If a visual scan of our neighborhood littered with very large avalanches isn't enough to remind you, note that there have been two avalanche fatalities this week in central Colorado. One near Aspen, one near Breckendrige, and both failing on weak layers that lie buried here in our snowpack too. These are the same weak layers that lurk near and above treeline on north through east aspects that were buried by our "holiday slab" back in December. This video shows these weak layers last week, before they received the dramatic load of 2.6" of a water equivalent this past weekend. Often by the time the ski area shuts, it's full "game-on" in the back country. This year the never-ending Persistent Slab problem remains and a complacent "game-on" mind-set could get you in trouble. You're generally unlikely to trigger one of these avalanches failing near the ground, but these two recent accidents are sober reminders that the slim potential for deep and destructive avalanching hasn't gone away.
The good news is that the riding conditions are great on the other side of the compass. You'll find smooth, and generally safe conditions on most slopes facing southeast to west. Head to the sun, and you can apply your usual spring habits. Start early, drop the summits while the mountain tops remain slightly firm, enjoy perfectly smooth surfaces through the mid-mountain and hope you make it out the valley floor before the trap doors of wet snow open each afternoon. Don't stay too late to avoid routine afternoon wet snow concerns. If you sink into the snowpack past your ankles, it's time to call it for the day on that slope. If you do head to the shady side, your best approach is to avoid steep shallow areas of snow, particularly shallow areas where the snowpack tapers up towards recently drifted steep slopes on north through east aspects. If you choose to travel on the deep snow areas near and above treeline, and you'll be much less likely to waken these beasts.
A significant rain on snow event this past weekend saturated our snowpack to over 11,000 feet on all aspects, causing a raucous wet slab cycle (and this observation too). Now with several days since the rain, that water has mostly drained towards the ground and following a few good freeze / thaw cycles, the lower elevation slopes are generally stable, where snow still remains. During the afternoon, consider the potential for small loose wet slides, but otherwise generally safe conditions prevail well below treeline.
By Friday, we've got another cold and snowy day in the forecast, so expect the reset button to get pressed. We'll have cold snow on the sunnies for a day, then a couple days of transitional conditions where the will softest surfaces will be in the shade. Stay tuned.