0845 AM PST Sunday, March 10, 2002...CORRECTED... ZONE AVALANCHE FORECASTS..... OLYMPICS...WASHINGTON CASCADES NEAR AND WEST OF THE CREST...MT HOOD AREA... ....................AVALANCHE WATCH..................... Considerable avalanche danger below 7000 feet Sunday, increasing significantly later Sunday night and Monday and becoming high below 7000 feet. Avalanche danger slightly decreasing later Monday mainly lower elevations becoming high above 4 to 5000 feet and considerable below Monday night. EAST SLOPES WASHINGTON CASCADES.... Considerable avalanche danger above 5 to 6000 feet and moderate below Sunday, gradually increasing Sunday night and Monday and becoming high above 6000 feet, considerable from 4 to 6000 feet and moderate below 4000 feet late Monday. SNOWPACK ANALYSIS..... In the Olympics, Mt Hood area and most areas near and west of the Cascade crest in Washington, gradually increasing amounts of new relatively low density snow were received last week--with amounts ranging from 1 to over 3 feet, with slightly higher density snow received in most areas on Saturday. While much of the earlier snowfall was accompanied by relatively light winds making for relatively stable and excellent skiing, snowboarding or snowmobiling, in most instances the new snow formed a relatively weak bond with either the old rain crust formed in late February or a more recent sun or melt-freeze crust from early last week. In lower elevation wind sheltered areas where wind action has been minimal and where a slightly better bond of new snow to the old surface exists, relatively cohesionless and soft surface snow still exists above the crust with most avalanche activity confined to small loose sluffs or small slabs with little propagation. However, in most other areas where winds have increased of late, much more cohesive soft slabs have developed with higher density snow lying over very low density snow over a crust. Also, some faceting of the snow has occurred near and just above either of the old crusts and this has helped to further weaken the attachment of the recent snow to these relatively smooth bed surfaces. While on most sun-exposed slopes recent surface hoar was destroyed prior to burial, small areas of hoar frost may still exist near the crust on wind and sun sheltered slopes. As a result of this overall snow pack structure, a considerable avalanche danger exists in most of the Olympics and Cascades near and west of the crest, with soft slabs of 1 to 2 feet probable in most steeper wind loaded terrain-mainly southeast through northeast exposures near higher ridgelines. Near the Cascade passes shifting winds during the last few days may have loaded both east and west exposure slopes. Field reports indicate that several 1 to 2 ft wind slabs were triggered by skiers and snowboarders Thursday through Saturday and more are probable on slopes showing evidence of wind transport. Although less new snowfall along the Cascade east slopes is resulting in a slightly lower danger, some shallow slabs are still probable near higher ridges and possible at lower elevations. SUNDAY.....CORRECTED.... Light to moderate showers should increase Sunday morning and early afternoon to light to moderate snow. Along with increasing ridge top winds and slightly rising freezing levels this should maintain or slightly increase existing avalanche danger with wind slabs of 1 to 2 feet or more remaining probable on wind loaded slopes, especially east and northeast exposures near higher ridges. Briefly decreasing showers and slightly lowering freezing levels are expected later Sunday afternoon and evening. However, moderate ridge top winds should help maintain existing danger with a slight decrease only expected at lower elevations as recent snowfall and shallower slabs begin to settle. SUNDAY NIGHT...MONDAY...MONDAY NIGHT.....CORRECTED... Light to moderate rain or snow should spread into the Olympics Sunday night and the Cascades early Monday, with moderate to heavy rain or snow likely Monday morning and early afternoon. Along with increasingly strong winds and rising freezing levels, this should produce a substantially increasing avalanche danger- especially near and west of the Cascade crest where generally high danger is expected. With higher density snow or rain falling on an already relatively unstable snow pack, increasingly sensitive and gradually larger slabs of 2 to 3 feet or more are expected with both natural and human triggered slides likely. Most slides should release much of the recent snowfall down either to the old late February crust or the melt-freeze crust from early last week, and while greatest danger should develop on northeast through southeast exposures, unstable snow may be found on a variety of aspects and slope angles-especially at lower elevations receiving rain. While the expected strong winds may scour the snow down to the crust on higher elevation wind exposed terrain, nearby lee slopes should be heavily loaded and probably lower in the path than normal. Slides that do release should quickly run relatively long distances on the relatively smooth sliding surface. As a result, back country travel in avalanche terrain is not recommended Monday with safest travel on windward ridges of lower angle slopes without steeper terrain above. Lowering freezing levels and more showery precipitation expected later Monday and Monday night should allow for a slight decrease in the danger at lower elevations. However moderate to heavy snow or snow showers should maintain generally high danger above 4 to 5000 feet where natural or human triggered wind slabs should remain likely. Although most slides expected after Monday afternoon should involve only the most recently deposited snow since the warming mid-day Monday, especially at lower elevations, isolated larger slides above 4 to 5000 feet may still involve all of the snow accumulated over the late February crust-which by now may total 4 to 5 feet or more in heavily wind loaded areas.