130 PM PST SUN DEC 16 2007 && ZONE AVALANCHE FORECASTS * WASHINGTON CASCADES NEAR AND WEST OF THE CREST GLACIER PEAK NORTHWARD- ...AVALANCHE WARNING FOR SUNDAY EVENING THROUGH MONDAY MORNING... High avalanche danger above 4000 feet and considerable below Sunday. Increasing high avalanche danger above 4000 feet and considerable below Sunday night and Monday morning. Avalanche danger slightly decreasing and becoming considerable below 7000 feet Monday afternoon and evening. * OLYMPICS, WASHINGTON CASCADES NEAR AND WEST OF THE CREST SOUTH OF GLACIER PEAK- ...AVALANCHE WARNING FOR SUNDAY EVENING THROUGH MONDAY MORNING... Considerable avalanche danger above 4000 feet and moderate below Sunday. Increasing high avalanche danger above 4000 feet and considerable below Sunday night and Monday morning. Avalanche danger slightly decreasing and becoming considerable below 7000 feet Monday afternoon and evening. * MT HOOD AREA- ...AVALANCHE WARNING FOR SUNDAY NIGHT THROUGH MONDAY MORNING... Considerable avalanche danger above 5000 feet and moderate below Sunday. Increasing high avalanche danger above 5000 feet and considerable below Sunday night and Monday morning. Avalanche danger slightly decreasing and becoming considerable below 7000 feet Monday afternoon and evening. * EAST SLOPES WASHINGTON CASCADES- Considerable avalanche danger above 5-6000 feet and moderate below Sunday. Increasing considerable avalanche danger above 4-5000 feet and moderate below Sunday night and Monday morning. Avalanche danger slightly decreasing and becoming considerable 5000 feet and moderate below Monday afternoon and evening. SNOWPACK ANALYSIS A firm crust was formed by the avalanche and rain event of early December. This crust has been covered by light amounts of snow and intermittent weak hoar frost in most areas since that time. Over the 24 hours ending Sunday morning Mt Baker received 16 inches of new snow, with about 6-8 inches at Stevens and Snoqualmie, and lighter amounts further south and along the east slopes. A similar but shallower structure might be expected along the Cascade east slopes. Some reports from Saturday include many easily triggered 12-14 inch slab avalanches by the Mt Baker ski patrol on north slopes from 45-5500 feet. Other reports include a skier triggered 1 meter deep avalanche on a north slope at about 5200 feet Hurricane Ridge. Reports on Turns All Year indicated unstable conditions at Stevens on Skyline Ridge and at Snoqualmie near Alpental. The Crystal ski patrol reported that a ski cut on a small test slope remotely triggered a 8-12 inch slab in the back country. Pockets of soft slab were reported by the Mt Hood Meadows ski patrol. Most of these avalanches were releasing down to or near the early December crust. This snow structure should generally become more unstable as it is loaded by heavy snowfall Sunday night and Monday morning. SUNDAY AND SUNDAY NIGHT Gradually increasing southwest crest level winds and snowfall should be seen Sunday with cool east winds in the Cascade passes. Strong southwest crest level winds and heavy snowfall should have begun by Sunday evening with continued cool east winds in the Cascade passes. The avalanche danger may increase by Sunday afternoon in the Olympics and north Cascades. We do not recommend back country travel in the Olympics and north Cascades by Sunday afternoon and elsewhere by Sunday evening. This weather should cause an increasing avalanche danger by Sunday evening and especially Sunday night with natural or triggered avalanches likely especially on lee slopes. A significant increase in the avalanche danger also seems likely Sunday night in the lower Cascade passes when cool east winds change to warmer west winds. MONDAY AND MONDAY NIGHT Strong west winds and heavy orographic snowfall should be seen in most areas Monday morning. This should continue to maintain and develop new slab layers on lee slopes. Triggered or natural avalanches in newer snow layers may step to deeper layers near or on the early December crust. We do not recommend back country travel through Monday morning. Decreasing west winds and snowfall should begin to be seen Monday afternoon and night. This should begin to decrease the avalanche danger Monday afternoon and night as new snow slightly stabilizes. Note however that another storm is indicated for Tuesday. &&