####018004272#### WWUS86 KSEW 012041 SABWA Summary Avalanche Forecast for Olympics and Washington Cascades Northwest Weather and Avalanche Center Seattle Washington 1240 PM PST Thu Mar 01 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 Thursday: High avalanche danger above 5000 feet and considerable below. Danger decreasing Thursday night. Friday: Increasing considerable danger above 3000 feet and moderate below. Danger further increasing Friday night. Saturday Outlook: Considerable avalanche danger above 3000 feet and moderate below. Washington Cascades east of the crest Thursday: High avalanche danger above 6000 feet and considerable below. Danger decreasing Thursday night. Friday: Increasing considerable danger above 4000 feet and moderate below. Danger further increasing Friday night. Saturday Outlook: Considerable avalanche danger above 4000 feet and moderate below. Snowpack Synopsis A strong series of storms has been pretty much pummeling the Olympics and Cascades with snow since about mid February. Many natural and triggered avalanches have been reported since that time. The most serious avalanches were caused by a persistent weak hoar frost layer from early February causing accidents and fatalities on 19 February. The latest storm began to cross the Olympics and Cascades Tuesday night. Snowfall for the 48 hours ending Thursday morning is in the 1-2 foot range near and west of the crest similar to previous storms. This brings snowfall totals mostly to the 6-10 foot range near and west of the crest since mid February. Yet another round of widespread skier triggered avalanches was reported by the ski area avalanche crews on Wednesday afternoon. Thursday Winds and snow showers should decrease on Thursday. A concern is new unstable storm layers that are likely to be found on steep lee slopes. Another concern is that sun or sun effects may activate new snow on steep slopes facing the sun. Back country travel in avalanche terrain is not recommended on Thursday. Ski area skiing would be a good choice on Thursday. Some stabilizing of new layers should occur by Thursday night. Friday Partly or mostly cloudy weather and little if any rain or snow should be seen during most of the daylight hours on Friday. Cool temperatures Thursday night and Friday morning and some stabilizing should decrease the extent of recent unstable storm layers and lower the avalanche danger a bit from Thursday. Small areas of these layers will probably still be present on steep lee slopes. Some light rain or snow and gradually warming temperatures should be seen by Friday afternoon. So natural or triggered damp snow avalanches seem likely mainly on steep slopes facing the sun but possibly on other steep slopes as well by Friday afternoon. Careful snowpack evaluation will be required on Friday and triggered avalanche should be likely. More rain or snow and further gradual warming should maintain or further gradually increase the avalanche danger Friday night. Saturday Outlook Further rain or snow and further gradual warming should be seen Saturday. This will maintain natural or triggered damp snow avalanche conditions on most steep slopes. Small areas of recent unstable storm layers on steep lee slopes will probably also still be active due to the loading by wet snow or rain and weakening by warmer temperatures. Natural or triggered avalanches should still be possible or likely on Saturday. 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. Ferber/Northwest Weather and Avalanche Center Seattle Washington References 1. http://www.nwac.us/ ####018003724#### WWUS86 KPQR 012041 SABOR Summary Avalanche Forecast for Mt Hood area Northwest Weather and Avalanche Center Seattle Washington 1240 PM PST Thu Mar 01 2012 This forecast applies to back country avalanche terrain below 7000 feet and does not apply to developed ski areas or highways. Avalanche Forecast Mt Hood Area Thursday: High avalanche danger above 6000 feet and considerable below. Danger decreasing Thursday night. Friday: Increasing considerable danger above 4000 feet and moderate below. Danger further increasing Friday night. Saturday Outlook: Considerable avalanche danger above 4000 feet and moderate below. Snowpack Synopsis A strong series of storms has been pretty much pummeling the Olympics and Cascades with snow since about mid February. Many natural and triggered avalanches have been reported since that time. The most serious avalanches were caused by a persistent weak hoar frost layer from early February causing accidents and fatalities on 19 February. The latest storm began to cross the area Tuesday night. Snowfall for the 48 hours ending Thursday morning at Mt Hood is about 2 feet. This brings snowfall totals to about 6 feet at Mt Hood since mid February. Yet another round of widespread skier triggered avalanches was reported by the Meadows ski patrol on Wednesday afternoon. Thursday Winds and snow showers should decrease on Thursday. A concern is new unstable storm layers that are likely to be found on steep lee slopes. Another concern is that sun or sun effects may activate new snow on steep slopes facing the sun. Back country travel in avalanche terrain is not recommended on Thursday. Ski area skiing would be a good choice on Thursday. Some stabilizing of new layers should occur by Thursday night. Friday Partly or mostly cloudy weather and little if any rain or snow should be seen during most of the daylight hours on Friday. Cool temperatures Thursday night and Friday morning and some stabilizing should decrease the extent of recent unstable storm layers and lower the avalanche danger a bit from Thursday. Small areas of these layers will probably still be present on steep lee slopes. Some light rain or snow and gradually warming temperatures should be seen by Friday afternoon. So natural or triggered damp snow avalanches seem likely mainly on steep slopes facing the sun but possibly on other steep slopes as well by Friday afternoon. Careful snowpack evaluation will be required on Friday and triggered avalanche should be likely. More rain or snow and further gradual warming should maintain or further gradually increase the avalanche danger Friday night. Saturday Decreasing rain or snow but further gradual warming should be seen Saturday. This will maintain natural or triggered damp snow avalanche conditions on most steep slopes. Small areas of recent unstable storm layers on steep lee slopes will probably also still be active due to the loading by wet snow or rain and weakening by warmer temperatures. Natural or triggered avalanches should still be possible or likely at Mt Hood on Saturday. 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. Ferber/Northwest Weather and Avalanche Center Seattle Washington References 1. http://www.nwac.us/