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                  Summary Avalanche Forecast for Mt Hood area



   Northwest Weather and Avalanche Center Seattle Washington



   1243 PM PST Wed Feb 22 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-



   Wednesday: High avalanche danger above 5000 feet and considerable below

   with the greatest danger on lee slopes. Slowly decreasing danger late

   Wednesday and Wednesday night.



   Thursday: Considerable avalanche danger above 5000 feet and moderate

   below and slowly decreasing. Further slowly decreasing danger Thursday

   night.



Snowpack Synopsis



   Very strong warm frontal precipitation began late Monday lasting

   through Tuesday night followed by a strong cold frontal passage early

   Wednesday. This system deposited very heavy precipitation amounts at

   rising freezing levels along with very strong, mostly westerly winds.

   Cooling began early Wednesday with additional heavy precipitation

   falling with the associated cold frontal passage.  Precipitation

   amounts with this system mostly ranged from about 3 to nearly 5 inches

   of water equivalent as of early Wednesday. Rain or heavy wet snow fell

   to between 6 to 7000 feet on Mt Hood.



   The rain or wet heavy snow has loaded the 1 to 2 feet of colder lower

   density snowfall that accumulated late Friday and Saturday. The recent

   storm snow in turn overlies several buried layers including a thin

   crust noted by ski patrol at Mt Hood Meadows.  All this recent snowfall

   followed a dry and mild early February that produced a smooth hard

   melt-freeze crust.



Wednesday



   A strong cold frontal passage moved across the area early Wednesday

   causing heavy precipitation at cooling temperatures and very strong

   crest level westerly winds. This has likely begun to build new wind

   slab layers on lee slopes gradually to lower elevations. The greatest

   danger is expected on steeper north to southeast facing slopes above

   about 5000 feet, with shallower wind slabs forming on these aspects at

   lower elevations as well.



   Showers and strong westerly flow should continue through Wednesday

   causing further slow loading on lee slopes. Deep wet snow conditions

   are expected at lower elevations that have received heavy rains. These

   wet snow conditions should begin to gradually refreeze as cooling

   continues later Wednesday.



Thursday



   A relative break in the stormy recent weather pattern is expected

   Thursday as high pressure rebuild over the area. Expected partly to

   mostly cloudy weather with cool temperatures and light winds. This

   should allow for a decreasing danger Thursday as unstable storm or wind

   slab layers slowly settle and bond. However, the cold temperatures

   should slow this process and unstable slab layers are likely to persist

   in steeper lee terrain at higher elevations. Careful snowpack

   evaluation, cautious routefinding and conservative decision-making will

   be essential in higher elevation terrain.



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   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/