####018004066#### WWUS86 KPQR 101948 SABOR Summary Avalanche Forecast for Mt Hood area Northwest Weather and Avalanche Center Seattle Washington 1147 AM PST Sat Mar 10 2012 This forecast applies to back country avalanche terrain below 7000 feet and does not apply to developed ski areas or highways. Updated...Corrected second day wording... Avalanche Forecast Mt Hood area- ...Avalanche Watch for later Sunday... Saturday and Saturday night: Moderate avalanche danger above 4000 feet and low below slightly increasing Saturday and more significantly increasing Saturday night...becoming considerable on lee slopes above 5000 and moderate elsewhere. Sunday and Sunday night: Considerable avalanche danger above 5000 feet and moderate below further increasing Sunday and becoming high on lee slopes above 5000 feet and considerable elsewhere. Further slowly increasing danger Sunday night. Snowpack Synopsis Recent Weather, Snow Pack and Activity: Freezing rain last Friday night and early Saturday was followed by warm dry weather over the weekend at Mt Hood. This produced a strong surface crust to high elevations on Mt Hood. A cold front crossed the Northwest Monday followed by an upper trough Monday night. Southwest winds changed to northwest winds with cooling. Mt Hood received a total of about 10-14 inches of storm snow as of Tuesday morning. Some local new soft and wind slab layers formed over the strong crust with triggered or explosive slab releases reported Tuesday. A dry and sunny day Wednesday was followed by further warming and some filtered susnhine on Thursday and futher warming with filtered sunshine Friday. This allowed for snowpack settlement, some mostly shallow wet loose slides and increasing surface crust formation on many slopes with only higher elevation shaded terrain still harboring diminishing amounts of damp powder. Saturday and Saturday night Briefly increasing light rain or snow with moderate crest level winds are expected Saturday as a greatly weakened front crosses the area. However, this should be followed by increasing moderate rain or snow mid-late afternoon, with periods of moderate to heavy snow...lowering freezing levels and increasing winds overnight. This weather should produce a more significant danger increase overnight...especially on higher elevation lee terrain. Concern #1: Initially small and shallow new wind slabs developing on higher elevation lee slopes Saturday should increase Saturday night. This should make careful snowpack evaluation essential in higher terrain later Saturday. Sunday and Sunday night Moderate to heavy snow should transition to moderate to heavy snow showers on Sunday along with moderate ridgetop winds and further cooling. This should continue to produce a more general and significant increase in the danger. While showers should briefly decrease late Sunday and Sunday night ahead of a third stronger disturbance due in Monday, increasingly strong ridgetop and pass winds likely overnight should help maintain existing danger levels. Concern #1: Deepening wind slabs on a variety of lee slopes and increasing storm slab deposits: Deeper storm layers should build over earlier deposited storm snow and underlying crust layers or older settled snow. As a result, increasingly dangerous avalanche conditions are expected Sunday and travel on any wind loaded terrain is not recommended. 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/