430 PM PST FRI FEB 8 2008...corrected && ZONE AVALANCHE FORECASTS * OLYMPICS- WASHINGTON CASCADES- MT HOOD AREA- ...AVALANCHE WARNING FRIDAY AFTERNOON THROUGH SATURDAY AFTERNOON... HIGH avalanche danger Friday afternoon and evening increasing becoming EXTREME danger below 7000 feet Friday night through Saturday afternoon. Widespread natural avalanches are certain Friday night and early Saturday with possible large destructive slides. Travel in avalanche terrain should be avoided. Slightly decreasing danger late Saturday afternoon but increasing again Saturday night. OUTLOOK SUNDAY- High avalanche danger above 4 to 5000 feet and considerable below. SNOWPACK ANALYSIS Strong moist westerly flow has been piling up the snow throughout the Olympics, Washington Cascades and Mt Hood area over the past four days along with very strong winds. Generally 3 to 6 feet have accumulated over the past four days, with 1 to 3 feet along the east slopes. Crest level winds during this period have averaged 25 to 40 mph with typical gusts to 70 to over 100 mph and predominantly from the west. This has developed deep unstable wind slab layers on lee slopes while the strong winds have scoured much new snow on windward exposed slopes. Widespread natural avalanches occurred early Thursday during a brief warming trend. Cooling, previous natural releases and significant general snow pack settlement have lead to a gradually decreasing danger since early Thursday. However, new unstable layers have rapidly refilled slide paths as well as formed new unstable cornices along ridges. At the present time we feel back country travelers should err on the side of caution and avoid travel in avalanche terrain. It remains unclear what the sliding surfaces have been with most of the recent avalanche activity. Likely, most in storm layers of density changes, however some slides have likely broken down to a more widespread crust of variable strength formed in mid January during the fair weather...remember the fair weather? It is hard to say how the upcoming slide cycle will behave with such deep but semi-consolidated upper snowpack with unknown or undefined sliding layers. We may get slides in the upper snow layers that can break down to older layers of January, or possibly a December crust, maybe even the ground in areas with a shallower snowpack such as some east slope locales. At any rate, we definitely have the potential for some large and impressive avalanches! FRIDAY AND FRIDAY NIGHT Very strong crest level winds and moderate to heavy snow showers are expected Friday afternoon and evening. This should continue to build unstable slab layers on lee mostly easterly aspects. Also, large cornice formations should continue to build along ridges. Natural or triggered avalanche should continue to be likely. We are not recommending back country travel in avalanche terrain Friday. Warming with additional moderate to heavy snow changing to rain at mid and lower elevations Friday night should lead to a widespread natural avalanche cycle with some large and possibly destructive slides possible. Travel in avalanche terrain should be avoided Friday night. SATURDAY AND SATURDAY NIGHT Further warming is expected early Saturday with additional snow and or rain producing a widespread natural avalanche cycle by early Saturday morning. This should lead to an extreme danger with possible large destructive avalanches. Gradually decreasing rain or snow in the south and central areas later Saturday should allow for a slow decrease in danger. However, continued rain or snow in the north should maintain high to extreme danger. A cold front by early Sunday should allow for a shift to new unstable dangers and maintain a generally high danger. Travel in avalanche terrain should be avoided Saturday through Saturday night. OUTLOOK SUNDAY Moderate to heavy rain or snow at cooling temperatures but with strong westerly winds should build new unstable slab layers and reload slide paths that may have slide earlier in the storm cycle. This should maintain a high danger at higher elevations where travel in avalanche terrain is still not recommended. &&