####018004902#### WWUS86 KPQR 161820 SABOR Summary Avalanche Forecast for Mt Hood area Northwest Weather and Avalanche Center Seattle Washington 1120 AM PDT Fri Mar 16 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- Friday and Friday night: Considerable avalanche danger above 5000 feet and moderate below Friday. Danger slightly increasing Friday night. Saturday and Saturday night: Considerable avalanche danger above 5000 feet and moderate below slightly increasing Saturday, mainly higher elevation lee slopes. Greatest danger developing on north through west exposures early Saturday and north through east exposures mid-late Saturday. Slightly decreasing danger expected Saturday night. Sunday outlook: Considerable avalanche danger above 6000 feet and moderate below slightly increasing mainly sun exposed terrain midday and afternon hours. Danger decreasing late Sunday. Snowpack Synopsis A strong storm Thursday produced strong winds, significant warming and heavy snow, wet snow or rain. As this warmer storm followed a series of cold storms that resulted in substantial accumulations of colder and weaker snow layers, the resulting upside down snowpack resulted in a high to extreme danger on Thursday along with a very sensitive snowpack, significant avalanche activity, some larger slide releases and significant settlement of the recently received snowfall. Since the warming ended mid-late Thursday afternoon, gradually colder temperatures overnight into early Friday have combined with previous slide activity, substantial settlement, and slow refreezing and strengthening of surface snow layers to allow for both a danger decrease as well as a slow transition from danger primarily involving the old and large amounts of snow received since last Saturday to that involving newly developing wind slabs over the older and still stabilizing slabs in the upper part of the snowpack. Friday and Friday night Moderate snow showers and winds should decrease and become light to moderate later Friday morning and afternoon, along with continued low freezing levels. Along with relatively light winds, this weather should not affect current danger levels significantly. However, despite the danger decrease from the recent high to extreme, human triggered slides should remain possible to likely on wind loaded terrain...depending on elevation. Also, any slopes receiving sun breaks between decreasing showers Friday afternoon should also see a slight increase in the danger. Finally, recent cornice formations have been quite large and may be unpredictable...as a result, such large overhangs as well as the slopes beneath them, should be avoided. Increasing and shifting winds likely late Friday and Friday night along with developing light to moderate snow overnight should begin to increase the danger on some new lee slopes receiving wind transport. Saturday and Saturday night Light to moderate snow should increase early-mid Saturday, followed by slowly decreasing light to moderate snow later Saturday. Along with moderate but shifting winds and continued low freezing levels, this should produce a slight increase in the considerable avalanche danger on wind affected lee terrain at mid and higher elevations and help maintain moderate danger at lower elevations. Decreasing light showers and winds along with further cooling late Saturday should begin a slow decrease in the danger...however cold temperatures should slow the stabilization process. Sunday Outlook Partly cloudy and cool weather Sunday with light snow showers slightly increasing midday and afternoon hours should not affect the overall danger significantly. However...in areas receiving sun breaks between showers, a generally increased danger is expected on sun exposed terrain and back country travelers should use increasing caution in areas affected by the sun. Also, recent large cornice formations may continue to be quite weak and suceptible to the destabilizing effects of sunshine. Decreasing light showers, light winds and some clearing Sunday night should help to slowly decrease the danger. 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. Moore/Northwest Weather and Avalanche Center Seattle Washington References 1. http://www.nwac.us/####018005902#### WWUS86 KSEW 161820 SABWA Summary Avalanche Forecast for Olympics and Washington Cascades Northwest Weather and Avalanche Center Seattle Washington 1120 AM PDT Fri Mar 16 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- Friday and Friday night: Considerable avalanche danger above 5000 feet and moderate below Friday. Danger slightly increasing Friday night, mainly south. Saturday and Saturday night: Considerable avalanche danger above 5000 feet and moderate below slightly increasing Saturday, mainly higher elevation lee slopes. Greatest danger developing on north through west exposures early Saturday and north through east exposures later Saturday. Slightly decreasing danger expected Saturday night. Sunday outlook: Considerable avalanche danger above 6000 feet and moderate below Sunday except slightly increasing danger mainly sun exposed terrain midday and afternon hours. Danger decreasing late Sunday. Washington Cascades east of the crest- Friday and Friday night: Considerable avalanche danger above 6000 feet and moderate below Friday. Danger slowly decreasing Friday night. Saturday and Saturday night: Considerable avalanche danger above 6000 feet and moderate below slightly increasing Saturday, becoming considerable on lee slopes above 5000 feet and increasing moderate elsewhere. Greatest danger developing on north through west exposures early Saturday and north through east exposures later Saturday. Slightly decreasing danger expected Saturday night. Sunday outlook: Considerable avalanche danger above 6000 feet and moderate below slightly increasing mainly sun exposed terrain midday and afternon hours. Danger decreasing late Sunday. Snowpack Synopsis A strong storm Thursday produced strong winds, significant warming and heavy snow, wet snow or rain. As this warmer storm followed a series of cold storms that resulted in substantial accumulations of colder and weaker snow layers, the resulting upside down snowpack resulted in a high to extreme danger on Thursday along with a very sensitive snowpack, several avalanche cycles, some larger to very large slide releases and significant settlement of the recently received snowfall. Since the warming ended mid-late Thursday afternoon, gradually colder temperatures overnight into early Friday have combined with previous slide activity, substantial settlement, and slow refreezing and strengthening of surface snow layers to allow for both a danger decrease as well as a slow transition from danger primarily involving the old and large amounts of snow received since last Saturday to that involving newly developing wind slabs over the older and still stabilizing slabs in the upper part of the snowpack. Friday and Friday night Moderate snow showers and winds should decrease and become light to moderate later Friday morning and afternoon, along with continued low freezing levels. Along with relatively light winds, this weather should not affect current danger levels significantly. However, despite the danger decrease from the recent high to extreme, human triggered slides should remain possible to likely on wind loaded terrain...depending on elevation. Also, any slopes receiving sun breaks between decreasing showers Friday afternoon should also see a slight increase in the danger. Finally, recent cornice formations have been quite large and may be unpredictable...as a result, such large overhangs as well as the slopes beneath them, should be avoided. Increasing and shifting winds likely late Friday and Friday night along with light to moderate snow developing in the south and spreading slowly northward overnight should begin to increase the danger on some new lee slopes receiving wind transport. Saturday and Saturday night Light to moderate snow should increase and spread northward early-mid Saturday, followed by slowly decreasing light to moderate snow later Saturday. Along with moderate but shifting winds and continued low freezing levels, this should produce a slight increase in the considerable avalanche danger on wind affected lee terrain at mid and higher elevations and help maintain moderate danger at lower elevations. Decreasing light showers and winds along with further cooling late Saturday should begin a slow decrease in the danger...however cold temperatures should slow the stabilization process. Sunday Outlook Partly cloudy and cool weather Sunday with light snow showers slightly increasing midday and afternoon hours should not affect the overall danger significantly. However...in areas receiving sun breaks between showers, a generally increased danger is expected on sun exposed terrain and back country travelers should use increasing caution in areas affected by the sun. Also, recent large cornice formations may continue to be quite weak and suceptible to the destabilizing effects of sunshine. Decreasing light showers, light winds and some clearing Sunday night should help to slowly decrease the danger. 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. Moore/Northwest Weather and Avalanche Center Seattle Washington References 1. http://www.nwac.us/