Wednesday, February 24, 2016

Sunshine and Avalanches

February 24th

Note the clean crown line,
indicative of slab avalanches .
After a wintery weekend at Mount Rainier, the clouds parted and the sun came out yesterday. However, along with the sun came strong easterly flow, producing moderate winds in the Paradise area. The temperatures stayed low yesterday, and the weekend snow was still quite soft, allowing it to be transported by the wind. Climbing rangers were out doing snow observations yesterday and noted blowing snow, and wind transport onto west and southwest aspects. The wind can provide for dramatic effects on avalanche conditions, scouring some places, and leaving large depositions in others. These depositions can be quite firm, and create the potential for slab avalanches.

Red pin near the "n" in Point
 is the avalanche location.
Brown switchbacking line is
common skin track up
Panorama Point
Yesterday, and today's NWAC avalanche forecast called for this possibility. Wind loading is a common occurrence around here in the winter time, with the typical wind flow for this area coming from the southwest, which transports snow to north-southeast aspects. One can almost set their watch to it if a windy storm passes through. Yesterday's occurrence is a little more rare, wind slab formation on west-southwest aspects. Today while out patrolling the Paradise area, climbing rangers noted a substantial wind slab avalanche on a west facing aspect, at approximately 6,800 feet. While this avalanche was not likely to bury anyone, had it gone slightly farther, over another roll over, it could have been much more disastrous. And an unsuspecting skier or snowshoer in the wrong place at the wrong time certainly could have been injured by this avalanche.   Similar aspects or wind loaded features should be suspect, and avoided while traveling in the backcountry until the wind slab problem has had a chance to settle. 

Just remember, when coming up to go for a ski or snowshoe,
not only check the current forecast but go back a few days to find out what conditions have been occurring on the mountain recently. While the current forecast is valuable, knowing the history of what has been affecting the snowpack and conditions can be equally important. The link to the Northwest Avalanche Center, above, is a great resource for mountain weather and avalanche forecasts. They do great work! The sun should be out tomorrow with spring like conditions, so grab your sunscreen, avalanche gear, skis or board and come on up for some winter fun!