830 AM PST Sunday, December 29, 2002 ZONE AVALANCHE FORECASTS..... OLYMPICS....WASHINGTON CASCADES NEAR AND WEST OF THE CREST.... Considerable avalanche danger above 5 to 6000 feet and moderate below Sunday, gradually decreasing through Sunday evening. Increasing avalanche danger late Sunday night and early Monday becoming considerable above 4000 feet and moderate below. Slightly decreasing danger later Monday, but remaining considerable above about 4000 feet and moderate below. MT HOOD AREA... EAST SLOPES WASHINGTON CASCADES.... Considerable avalanche danger above 6000 feet and moderate below Sunday, gradually decreasing through Sunday evening. Increasing avalanche danger late Sunday night and early Monday becoming considerable above 4 to 5000 feet and moderate below. Slightly decreasing danger later Monday, but remaining considerable above about 4 to 5000 feet and moderate below. SNOWPACK ANALYSIS..... Most areas of the Olympics and Washington Cascades received 2 to 6 inches of new snow over the past 24 hours. Active weather over the past five days has now deposited between 20 to 40 inches of new snow in most areas with most areas along the east slopes receiving 15 to 20 inches. The key elements within the snow pack structure now consist of the rain crust formed in mid December with the recent heavy snows of the past week overlying it with several potential buried weak layers from 6 to 12 inches above the crust. Clearing last weekend allowed widespread surface hoar to form in many areas both west and east of the crest. This layer was subsequently buried by a light snowfall last Tuesday in most areas that fell with light winds. Additional low-density snow layers were deposited before heavy wet snow and or strong winds Thursday and Friday deposited denser layers or wind slab over these weak layers. Avalanches releasing on this buried surface hoar layer were seen earlier this week in the Mission Ridge area and on Saturday in the Crystal Mountain area. Ski area avalanche crews at Crystal Mountain on slopes that had not previously been controlled triggered numerous slab releases Saturday. These slides ranging from 1.5 feet to 5 feet deep released on buried surface hoar formed last weekend snow with one slide triggered from about a 20-degree slopes angle above a steep slope. These slide starting zones ranged from about 6300 to 6800 feet and were north facing. The wind slabs that released were formed during strong winds at fluctuating temperatures during precipitation events over the past few days. Numerous weak layers of low- density snow or the buried surface hoar layer along with the overlying wind slabs are maintaining a considerable avalanche danger, especially at higher elevations where winds have been strongest. Triggered slab releases are probable on lee slopes, mainly ranging from northerly through southeasterly facing above about 5 to 6000 feet. At lower elevations lighter winds have transported less snow and therefore a slightly lower danger exists, however backcountry travelers should continue to use caution and avoid steep open slopes that may have received wind deposited snow. SUNDAY... Decreasing clouds and diminishing winds Sunday should lead to a slowly decreasing danger. However, previously formed unstable wind slabs should maintain a considerable danger above about 4 to 5000 feet where triggered slab releases are probable on lee slopes, especially near ridges. Increasing winds, slowly rising freezing levels and increasing rain or snow late Sunday night should produce an increase in the avalanche danger. MONDAY... Heavy snow and very strong ridge top winds early Monday should lead to an increasing danger, especially at higher elevations were new unstable wind slabs should develop on a variety of aspects, mainly north through northeast facing, except for some west facing slopes near the lower Cascade passes. Some deeper slide releases are possible as slides initializing in the new snow layers may step down to deeper layers or possibly the mid- December rain crust now buried some 2 to 5 feet in most area.