The avalanche conditions were caused by heavy snowfall followed by rising temperatures.
Local officials said the slide had not been forecast, although avalanche conditions were rated as hazardous.
Avalanche conditions in the area were moderate at the tree line and considerable in the alpine area, meaning that natural avalanches were possible, said Dave Skjonsberg of the Avalanche Control Center.
www.avalanche.org Avalanche conditions in places like Mount Shasta, Calif.; Sun Valley, Idaho; and Glacier National Park in Montana, with links to Europe and snow and weather forecast pages.
Two rangers on skis, Jim Giglento and Gary Hodgson, were on patrol in the area, checking avalanche conditions, and within 40 minutes had found the five survivors, the lieutenant said.
In late July the party succeeded in putting a camp on the North Col, but dangerous avalanche conditions kept them off the mountain.
The Avalanche Center lacks a polished presentation and, at times, an intuitive navigation scheme, but by clicking to different states and mountains, users can see areas of high avalanche probability, and read about factors that contribute to avalanche conditions.
Pelchat said that skiers and snowboarders interested in hiking up to Tuckerman Ravine need to pay attention to avalanche conditions posted at ranger outposts in the area, or they can log onto the Worldwide Web at www.mountwashington.org.org
Faced with the prospect of route-finding through potential whiteout and/or avalanche conditions with an inexperienced party, we made the smart decision late that night and changed our plans.
A rapid series of "whoomps" skittered beneath the surface like lightning strikes, the sound of a recently fallen layer of snow compressing beneath us and a sign of potential avalanche conditions.
