0810 AM PST Thursday, December 11, 2003 ZONE AVALANCHE FORECASTS.....AMENDED... WASHINGTON CASCADES NEAR AND WEST OF THE CREST...OLYMPICS... Moderate avalanche danger below 7000 feet increasing late Thursday afternoon and night and becoming considerable above 3 to 4000 feet and moderate below early Friday. Further slightly increasing danger expected on Friday with a slight decrease in the danger late Friday. MT HOOD AREA.... N/A EAST SLOPES WASHINGTON CASCADES.... N/A SNOWPACK ANALYSIS..... In most areas, from 6 to about 20 inches of new increasingly low density snow have accumulated since rising freezing levels produced a slightly firmer surface of either a weak crust or higher density one finger hardness snow late last week. Below this first crust or higher density snow, several layers of older slowly settling snow lie over a much stronger crust formed as a result of heavy rainfall in early December. This older crust now lies about 2-5 feet beneath the snow surface in most areas. While some wind transport last weekend had produced some 1-2 ft skier and explosive triggered slabs Sunday and Monday, slow settlement since early this week has decreased the potential for slides releasing on the older firmer surface from late last week. Although much of the most recent new relatively light amounts of low density snowfall generally had accumulated slowly without much wind transport prior to Tuesday, briefly increased winds on Tuesday in most areas produced slightly more cohesive and slabbier surface snow. Along with further light low density snowfall on Wednesday, areas of surface hoar that developed in some areas Monday night and more sporadically last night, this snow structure and recent weather have helped to maintain a moderate danger with human triggered soft slabs possible, mainly on steeper northeast through northwest facing slopes near higher ridges or west facing slopes near the Cascade passes. Travelers should be aware that in places where surface hoar formed Monday night-mostly in north-central Washington, the low density snow received in most areas either Tuesday or Wednesday has probably buried this weak layer intact. This snow structure is likely to form a very unstable combination when loaded by higher density snowfall expected Thursday night and Friday, and even more so mid-late Saturday, and should be closely monitored. FRIDAY... While moderate to occasionally heavy rain or snow should decrease and become more showery early Friday, increasing moderate to occasionally heavy showers are expected to develop later Friday morning and afternoon. Along with moderate to strong winds and lowering freezing levels this should help to maintain or slightly increase existing moderate to considerable danger, especially on wind loaded terrain. Mainly westerly winds should shift heavy loading and greatest danger from new slabs onto northeast through southeast exposures in all areas, although travelers should remember that west and northwest exposure slopes were recently loaded as well. Gradually decreasing winds and showers Friday night should allow for a slow decrease in the danger.