Thursday, May 15, 2008

Weather and Avalanche Advisory

Here's a SPECIAL weather and avalanche advisory for the next few days:

A major change in the weather pattern is underway in the Northwest Thursday and should persist through this weekend. Bluebird skies and high temperatures will significantly raise avalanche hazard Friday through the weekend on Mt Rainier.

If you are considering any climbing or skiing at or around Mt. Rainier, exercise extreme caution in avalanche terrain. Weather reports indicate that the current freezing level will rise above 14,000 feet, resulting in unstable conditions through the next few days.

Quick lesson: moisture from the snow surface will seep and lubricate layers further down in the snowpack, creating weakness as it percolates to the ground. Slopes 30 degrees or steeper on east through south through west aspects are of special concern. Do not assume that because the concern is wet-slab release that these avalanches will run slow or short.

If you are considering climbing the upper mountain, be advised that areas of the mountain have a full winter snowpack with significant wind-loaded slopes that are seeing their first transition cycle of the season. Areas such as the top of Disappointment Cleaver and Gibraltar Ledges are of special concern. Further down the mountain, the steep slope up to Panorama Point is also suspect due to its steep pitch and south-facing aspect.

Backcountry travelers should also avoid slopes below cornices or gullies and flat areas below avalanche run-out zones. Remember that boot or ski penetration of more than a few inches can indicate that snow is becoming significantly unstable on steep slopes. Finally, if you do plan on skiing or riding in the backcountry snow, please wax your skis to make your descent easier to reduce drag in sloppy conditions, and falls that may result in injury.*
*Portions of this advisory comes from the Point Forecast for Mt Rainier/NOAA and the Northwest Avalanche Center.