####018003503#### WWUS86 KSEW 272050 SABWA Summary Avalanche Forecast for Olympics and Washington Cascades Northwest Weather and Avalanche Center Seattle Washington 1249 PM PST Mon Feb 27 2012 This forecast applies to back country avalanche terrain below 7000 feet and does not apply to developed ski areas or highways. Avalanche Forecast Olympics- Washington Cascades near and west of the crest- Monday: Considerable avalanche danger above 4000 feet and moderate below. Tuesday: Considerable avalanche danger below 7000 feet early Tuesday, increasing danger afternoon becoming high above 6000 feet on lee slopes and considerable below. Further increasing danger Tuesday night. Washington Cascades east of the crest- Monday: Considerable avalanche danger above 4000 feet and moderate below. Tuesday: Considerable avalanche danger above 4000 feet and moderate below early Tuesday. Increasing danger late afternoon and night with a further increasing danger Tuesday night. Snowpack Synopsis Another strong storm cycle began early Friday with heavy snowfall at cooling temperatures with strong south to southwest crest level winds Friday through Saturday. Storm snow totals from early Friday through Monday morning for most areas have been 2 to 3 feet at protected lower elevation study plots. The recent storm and heavy wind loading produced another significant avalanche cycle over the past few days, with many natural or triggered slab releases, including some reported close calls. It appears most recent slide activity has involved mainly newer storm snow layers with most crowns in the 1 to 3 foot range. Monday High pressure is rebuilding over the area Monday providing a break in the recent storm cycles. Sunshine is expected with light winds and cool temperatures. This should allow recent storm and wind slabs to further slowly settle and stabilize. However, unstable wind slabs should persist in previously loaded areas. Triggered slides may need greater weight or load to initiate a slide. Some strong crest level east winds early Monday may have transported loose surface snow to lee west facing slopes near ridges building some shallow new slab layers. Tuesday Another frontal system will gradually move into the area Tuesday bringing increasing winds and snowfall. Winds should increase midday Tuesday with precipitation Tuesday afternoon increasing late Tuesday and Tuesday night. This weather should cause a gradual increase in the danger during the day Tuesday with a more significant increase late Tuesday and Tuesday night. Initially wind transport should begin loading northwest through northeast facing slopes at higher elevations where winds are stronger. Additional snowfall and strong winds should build deeper new unstable slab layers, adding additional loads to more deeply buried weak layers, including the persistent layer from early February. n/a n/a NWAC weather data and forecasts are also available by calling 206-526-6677 for Washington, 503-808-2400 for the Mt Hood area, or by visiting our Web site at www.nwac.us. Kramer/Northwest Weather and Avalanche Center Seattle Washington References 1. http://www.nwac.us/ ####018003500#### WWUS86 KSEW 272050 SABWA Summary Avalanche Forecast for Olympics and Washington Cascades Northwest Weather and Avalanche Center Seattle Washington 1249 PM PST Mon Feb 27 2012 This forecast applies to back country avalanche terrain below 7000 feet and does not apply to developed ski areas or highways. Avalanche Forecast Olympics- Washington Cascades near and west of the crest- Monday: Considerable avalanche danger above 4000 feet and moderate below. Tuesday: Considerable avalanche danger below 7000 feet early Tuesday, increasing danger afternoon becoming high above 6000 feet on lee slopes and considerable below. Further increasing danger Tuesday night. Washington Cascades east of the crest- Monday: Considerable avalanche danger above 4000 feet and moderate below. Tuesday: Considerable avalanche danger above 4000 feet and moderate below early Tuesday. Increasing danger late afternoon and night with a further increasing danger Tuesday night. Snowpack Synopsis Another strong storm cycle began early Friday with heavy snowfall at cooling temperatures with strong south to southwest crest level winds Friday through Saturday. Storm snow totals from early Friday through Monday morning for most areas have been 2 to 3 feet at protected lower elevation study plots. The recent storm and heavy wind loading produced another significant avalanche cycle over the past few days, with many natural or triggered slab releases, including some reported close calls. It appears most recent slide activity has involved mainly newer storm snow layers with most crowns in the 1 to 3 foot range. Monday High pressure is rebuilding over the area Monday providing a break in the recent storm cycles. Sunshine is expected with light winds and cool temperatures. This should allow recent storm and wind slabs to further slowly settle and stabilize. However, unstable wind slabs should persist in previously loaded areas. Triggered slides may need greater weight or load to initiate a slide. Some strong crest level east winds early Monday may have transported loose surface snow to lee west facing slopes near ridges building some shallow new slab layers. Tuesday Another frontal system will gradually move into the area Tuesday bringing increasing winds and snowfall. Winds should increase midday Tuesday with precipitation Tuesday afternoon increasing late Tuesday and Tuesday night. This weather should cause a gradual increase in the danger during the day Tuesday with a more significant increase late Tuesday and Tuesday night. Initially wind transport should begin loading northwest through northeast facing slopes at higher elevations where winds are stronger. Additional snowfall and strong winds should build deeper new unstable slab layers, adding additional loads to more deeply buried weak layers, including the persistent layer from early February. n/a n/a NWAC weather data and forecasts are also available by calling 206-526-6677 for Washington, 503-808-2400 for the Mt Hood area, or by visiting our Web site at www.nwac.us. Kramer/Northwest Weather and Avalanche Center Seattle Washington References 1. http://www.nwac.us/