200 PM PST SAT DEC 22 2007 && ZONE AVALANCHE FORECASTS * OLYMPICS, WASHINGTON CASCADES NEAR AND WEST OF THE CREST- ...AVALANCHE WARNING SATURDAY AND SUNDAY... Avalanche danger becoming high above 4000 feet and considerable below Saturday. Avalanche danger slightly decreasing Saturday night. Avalanche danger becoming high above 4000 feet and considerable below Sunday midday and continuing to Sunday night. * EAST SLOPES WASHINGTON CASCADES- Avalanche danger becoming considerable above 5000 feet and moderate below Saturday. Avalanche danger slightly decreasing Saturday night. Avalanche danger becoming high above 5000 feet and considerable below Sunday midday and continuing to Sunday night. * MT HOOD AREA- ...AVALANCHE WARNING SATURDAY AND SUNDAY... Avalanche danger becoming high above 5000 feet and considerable below Saturday. Avalanche danger slightly decreasing Saturday night. Avalanche danger becoming high above 5000 feet and considerable below Sunday midday and continuing to Sunday night. SNOWPACK ANALYSIS A stormy period brought about 4-7 feet of heavy snowfall to sites near and west of the crest over the past week. Many natural and triggered avalanches, triggered snowpack settlements (whumpfing) and propagating cracks were reported during that time especially from the ski areas. Some of these avalanches were as deep as the weakened crust from early December or even to the ground. A break in the weather on Friday allowed searchers to find and recover the body of a missing snowshoer in Edith Creek Basin near Paradise. This person was caught in a triggered avalanche last Tuesday. The day of lighter winds and little snowfall Friday also allowed the snowpack to slightly stabilize. Back country reports on the Friends of the Avalanche Center and Turns All Year web sites do not indicate any avalanches although skiers were sticking mostly to lower angle slopes. The Crystal Mountain ski area avalanche crew reported minimal results in the south back country with hand charge sized explosives. A large explosive gave a 2- 3 foot slab avalanche in the Crystal Mountain north back country. DETAILED FORECAST SATURDAY AND SATURDAY NIGHT A front will cross the Olympics and Cascades Saturday midday. This should cause increasing southwest crest level winds and moderate to heavy snowfall with a brief warming trend. About 5 to 15 inches of snowfall seems possible near and west of the crest on Saturday. The warming trend and avalanche danger increase might be most notable when winds change from cool east winds to warmer west winds in the lower Cascade passes Saturday afternoon. This weather is likely to cause new surface slab layers to build on lee slopes. Natural or triggered avalanches may entrain deeper layers. We recommend that backcountry travel near avalanche terrain be avoided on Saturday. SUNDAY AND SUNDAY NIGHT Another stronger front will cross the Olympics and Cascades Sunday afternoon. This should cause stronger increasing southwest crest level winds and heavier snowfall with another stronger warming trend Sunday midday through evening. Up to 10-20 inches of snowfall seems possible on Sunday midday to Sunday night. The stronger warming trend should be more efficient at building further deeper new slab layers on lee slopes. A change to rain should be seen in some areas Sunday afternoon. Natural or triggered avalanches may entrain deeper layers. We do not recommend backcountry travel near avalanche terrain Sunday midday through night. Potential deeper instability due to the buried crust formed early in December remains a concern. &&