January 21st-27th 2002 is Washington Avalanche Awareness Week 3 PM PST THURSDAY 24 JANUARY 2002 ZONE AVALANCHE FORECASTS..... WEST OLYMPICS...WASHINGTON CASCADE NEAR AND WEST OF THE CREST... ....................AVALANCHE WARNING.................. High avalanche danger below 7000 Thursday to Friday morning. Gradually decreasing avalanche danger Friday, becoming considerable below 7000 feet. MT HOOD AREA... ....................AVALANCHE WARNING.................. Considerable avalanche danger Thursday morning. Increasing high avalanche danger below 7000 Thursday afternoon to Friday morning. Gradually decreasing avalanche danger later Friday, becoming considerable below 7000 feet. EAST OLYMPICS AND HURRICANE RIDGE...WASHINGTON CASCADE EAST OF THE CREST... Considerable avalanche danger above 5000 feet and moderate below Thursday to Friday morning. Gradually decreasing avalanche danger later Friday, becoming considerable above 5-6000 feet and moderate below. SNOWPACK ANALYSIS.... Very strong winds, heavy snowfall and a warming trend was seen by later Wednesday. Snowfall for the past 24 hours ending Thursday morning ranges from about 10-14 inches at higher elevations, to about 4 inches at Snoqualmie and Crystal Mountain, to about 6-9 inches at Mt Hood, and much less along the Cascade east slopes. About 10 to 15 degrees F of warming was seen in the 24 hours ending Thursday morning at many sites. Snowfall totals for the past few days range from about 3-7 feet at sites near the Cascade crest. West to southwest winds on Wednesday night ranged to over 100 mph at some NWAC mountain top sites such as the top of White Pass. This weather is likely to have created more new slab layers on many steeper northeast to southeast aspects, with cross loading on other aspects, by Thursday morning. The periods of strong west to southwest winds and heavy snow the past few days are also likely to have previously created potential deep slab layers on similar aspects. Crusts and surface hoar layers from early January are now deeply buried on some slopes. Several human triggered avalanches and injury accidents have been reported this week, and most of these avalanches have been starting with recent slab layers and quickly stepping down to the hoar and crust layers. A group of skiers and snowboarders triggered a 16 inch to 4 foot by 80 foot wide slab at about 4500 feet on a south aspect at Stevens on Skyline on Monday, resulting in 4 partial and 1 complete burial, with some injuries. Another group of snowboarders triggered a 35-40 cm deep by 30-40 meter wide soft slab at Stevens on Monday on the south to southwest side of Cowboy Mountain at about 4600 feet, with injuries. A 2 to 6 foot slab by 300 yard wide slab was triggered at about 4400 feet on what appears to have been a north aspect at Snoqualmie Pass on Sunday, but no one was caught. An experienced patroller triggered a 1-2 foot slab at about 5000 feet on a 32 degree east to southeast aspect at Crystal Mountain on Tuesday and was carried into trees. But there have been no fatalities through Wednesday. Propagating cracks and easy Rutschblock failures at 7 and 16 inches below the surface were seen Wednesday in recent storm cycle layers at Paradise. Some windward aspects are also reported to be scoured to stable crust layers. Less danger is expected in the east Olympics and east of the Cascade crest where snowfall has been lighter, but caution is still warranted in those areas. Thursday..... Very strong west winds and increasing heavy snow is expected on Thursday and Thursday night. This will continue to create more slab layers on mainly steeper northeast to southeast aspects, but cross loading will be possible on other steep slopes. Natural and human triggered avalanches are expected Thursday. Back country travel near avalanche terrain is not recommended on Thursday. Friday..... The strong west winds should gradually decrease on Friday, with snow changing to snow showers, and a cooling trend. Winds and snow should initially decrease in the Olympics and north Cascades early Friday morning, and the south Cascades and Mt Hood area by Friday midday. This weather should allow previous slab layers to begin to partly stabilize later Friday. New snow layers are somewhat more likely to be stable due to decreasing snow densities. But slab layers are also likely to linger on many steeper northeast to southeast aspects, or other cross loaded aspects. Less danger is expected in the east Olympics and especially east of the Cascade crest where snowfall should be lighter. Persons who chose to travel in the backcountry so soon after a storm on Friday are recommended to stay on lower angle slopes, use great caution near steeper avalanche terrain, and periodically evaluate snow stability, especially near and west of the Cascade crest.