9 AM PST Monday 29 January 2001 ZONE AVALANCHE FORECASTS..... OLYMPICS. . .WASHINGTON CASCADES. . . Avalanche danger increasing Monday and becoming considerable above 4000 feet and moderate below. Avalanche danger slightly decreasing Tuesday, becoming considerable above 5000 feet and moderate below. MT HOOD AREA. . . Avalanche danger increasing Monday and becoming considerable above 5000 feet and moderate below. Avalanche danger slightly decreasing Tuesday, becoming considerable above 6000 feet and moderate below. SNOWPACK ANALYSIS.... In the Olympics and west of the Cascade crest, the upper snow pack generally consists of stable firm crusts and softer intermediate layers early Monday. The crusts were formed by rain that fell at warmer temperatures about a week ago and in early January. Newer surface snow at higher elevations in the north Cascades was seen to be eroded away or packed into wind crusts. On some slopes, smooth eroded or icy surfaces may act as smooth sliding surfaces for snow expected Monday. The deeper snowpack has been found to be firm and generally stable. But east of the Cascade crest underlying crust layers have been weakened by cooler temperatures, and may not be stable if loaded by significant new snowfall. On both sides of the crest on sheltered slopes, areas of about 1 cm surface hoar frost that developed the last couple days should also act as a weak layer for new snowfall. Monday..... About a week of dry weather is coming to an end on Monday morning. Initial southeast crest level winds should shift to strong southwest, with a switch from east to west in the Cascade passes. The switch may bring some initial warming at the passes before cooling takes over. Moderate to heavy snowfall is generally expected Monday in the Olympics and near and west of the Cascade crest. Initial lighter winds and cooler temperatures should be followed by stronger winds and heavier snowfall, which should promote unstable storm cycle profiles and new slab layers, mainly on north to east slopes at higher elevations and on more varied exposures near the passes. Surface hoar frost may act as weak layers on some slopes. Easy skier triggered 6-8 inch soft slab avalanches are already reported from Mt Hood on Monday morning. Backcountry travelers should use increasing caution near avalanche terrain. Snowfall and winds should decrease Monday night. Tuesday..... Slightly renewed light to moderate rain or snow is expected in the north Cascades Tuesday, with light rain or snow further south, generally at slightly warming temperatures. The overall decreased winds and snowfall should generally allow new storm cycle slab layers from Monday to settle and partly stabilize. Further snowfall in the north Cascades may continue to build or maintain unstable profiles and new slab layers, or load layers from Monday. New or lingering slab layers should be most likely on north to east slopes at higher elevations and in the north Cascades. Back country travelers should continue to use caution near avalanche terrain, and periodic stability evaluations are recommended.