9 am pst Monday 18 January 1999 ZONE AVALANCHE FORECASTS..... OLYMPICS, WASHINGTON CASCADES NEAR AND WEST OF THE CREST -----AVALANCHE WARNING-------- High avalanche danger above 4000 feet and considerable below on Monday. Avalanche danger decreasing Tuesday, becoming high above 5000 feet and considerable below. MT HOOD AREA -----AVALANCHE WARNING-------- High avalanche danger above 5000 feet and considerable below on Monday. Avalanche danger slightly decreasing Tuesday, becoming high above 5-6000 feet and considerable below. SNOWPACK ANALYSIS..... More heavy amounts of new snow have fallen in the Olympics and Cascades the past 24 hours. All sites in the Olympics and near and west of the Cascade crest are reporting 15 to 20 inches of new snow. This newer snow is relatively warm and dense in some areas, especially the south Cascades and Mt Hood area. This snow brings totals for the past 5 days to 40 to 50 inches. About 5-10 inches was seen the past 24 hours east of the crest, with about 10-20 inches the past few days. Very strong east or southeast winds were seen on Sunday, with periods of very strong west winds the previous couple days. These strong winds and fluctuating temperatures created weak layers in the new snow along with wind slab in many areas both west and east of the crest. The denser new snow and wind slab, along with underlying lower density snow and the weak layers, is creating instability in many areas. Numerous natural and triggered soft slab avalanches were seen on Sunday and Sunday night, both west and east of the Cascade crest. These avalanches were seen mainly on steep slopes, with snow sufficiently unconsolidated to reduce the instability on lower angle slopes. Easy shears are still being seen in snow pits on Monday morning. Therefore fairly widespread instability is still expected on steep slopes of varied aspects. Back country travel conditions are getting rather difficult with all the new snow, not to mention the potential instabilities, and skiers or snow boarders may do best by heading for a ski area. Monday..... Moderate to heavy snow should continue until Monday afternoon, with strong south to southwest crest level winds, and lowering snow levels. This should help maintain loads on underlying lower density snow and weak layers before it settles and stabilizes. New soft slab layers should also be expected. The most likely aspects for instability should be northwest to northeast aspects above tree-line. But instability may be present on other more varied aspects due to the varied winds. Back country travel near steep avalanche terrain is not recommended on Monday. Decreasing snow showers are expected Monday night. This may begin to allow for settling and stabilizing on some slopes. Tuesday..... A weak weather system should move mainly through Oregon Tuesday afternoon and evening. This should cause some renewed light to moderate snow fall, mainly in the south Cascades and Mt Hood area later Tuesday. Snow levels are also expected to stay rather low. Winds should generally decrease through Tuesday. These weather factors should allow weak layers in the deep snow to begin to consolidate and slightly stabilize. But new snow should also maintain loads on weak layers on some slopes and these slopes may remain unstable. Natural or triggered avalanche should still be likely near steep avalanche terrain at higher elevations on Tuesday. The safest travel at more moderate or lower elevations should be on windward lower angle slopes without steep terrain above.