900 AM PST WED JAN 30 2008
 
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ZONE AVALANCHE FORECASTS
* OLYMPICS-WASHINGTON CASCADES NEAR AND WEST OF THE CREST-
...AVALANCHE WARNING...

HIGH avalanche danger above 4000 feet and CONSIDERABLE 
below Wednesday. Increasing HIGH avalanche danger below 
7000 feet Wednesday night and Thursday.


* WASHINGTON CASCADES EAST OF THE CREST-
...AVALANCHE WARNING...

HIGH avalanche danger above 4-5000 feet and CONSIDERABLE 
below Wednesday. Increasing HIGH avalanche danger above 
4000 feet and CONSIDERABLE below Wednesday night and 
Thursday.


* MT HOOD AREA-
...AVALANCHE WARNING...

HIGH avalanche danger above 5000 feet and CONSIDERABLE 
below Wednesday. Increasing HIGH avalanche danger below 
7000 feet Wednesday night and Thursday.


SNOWPACK ANALYSIS
Fair cool weather helped form surface crusts and surface 
hoar frost in many areas in mid January. Storms began to 
cover these layers with very heavy snowfall starting last 
weekend.


A strong front crossed the Olympics and Cascades Tuesday. 
This caused strong west crest level winds and very heavy 
snowfall. New snow for the 24 hours ending this morning 
is 15-20 inches at Hurricane Ridge and most sites near 
and west of the crest. This brings the heavy snowfall 
totals since last weekend to 3-5 feet at most sites near 
and west of the crest. Temperatures and therefore snow 
densities have slightly and generally increased since 
last weekend. This is likely to have built especially 
deep new layers on lee slopes at higher elevations but on 
other slopes and to lower than usual elevations as well.


This should have caused an avalanche cycle in most areas 
of the Olympics and Cascades on Tuesday. Few back country 
reports are available. The Snoqualmie DOT crew reported 
an extensive natural avalanche cycle and multiple storm 
shear layers on Tuesday. Other fairly extensive storm 
cycle avalanches were reported from Stevens, Crystal and 
Mt Hood Meadows ski areas. A general upper snowpack 
structure should be deep recent snow over crust layers 
from mid January.


WEDNESDAY AND WEDNESDAY NIGHT
West winds and snow showers should decrease on Wednesday. 
This will allow deep new wind and storm cycle slab layers 
to begin to partly stabilize. Deep slab layers will 
remain most likely on lee slopes. This should be north to 
east aspects but should remain possible on other aspects. 
We expect triggered avalanches to remain probable 
especially Wednesday morning. Therefore we recommend that 
back country travelers stick to safer lower angle terrain 
on Wednesday and avoid steeper avalanche terrain. The 
next very strong storm should begin to move into the 
Northwest on Wednesday night. This should begin another 
avalanche cycle and another period of high avalanche 
danger.


THURSDAY AND THURSDAY NIGHT
The next front should cross the Olympics and Cascades 
Thursday morning. Very strong southwest crest level winds 
should change to westerly. Heavy snow at slightly warmer 
temperatures should change to moderate to heavy 
orographic snow showers. This should lead to another 
avalanche cycle Thursday. New deep wind or soft slab 
avalanches are most likely on lee slopes. This should to 
continue to be mainly north to east aspects but should be 
likely on other aspects as well. Natural and triggered 
avalanches are likely on Thursday. Avalanches may step 
down to layers from mid January. We do not recommend back 
country travel near avalanche terrain on Thursday. Back 
country travel is likely to be difficult due to deep new 
snow near and west of the crest. It should be a good day 
to head to a ski area as long as driving conditions are 
not to difficult as well. These conditions may last into 
Thursday night.

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