130 PM PST SUN DEC 2 2007
 
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ZONE AVALANCHE FORECASTS

* OLYMPICS-
.AVALANCHE WARNING SUNDAY AND MONDAY... 
Increasing high avalanche danger below 7000 feet Sunday 
morning. Extreme avalanche danger above 5000 feet and 
high below Sunday afternoon to Monday morning. 
Avalanche danger beginning to decrease Monday afternoon 
and night.


* WASHINGTON CASCADES NEAR AND WEST OF THE CREST-
.AVALANCHE WARNING SUNDAY AND MONDAY... 
Increasing high avalanche danger below 7000 feet Sunday 
morning. Extreme avalanche danger above 4-5000 feet and 
high below Sunday afternoon to Monday morning. 
Avalanche danger beginning to decrease Monday afternoon 
and night.


* WASHINGTON CASCADES EAST OF THE CREST-
.AVALANCHE WARNING SUNDAY AND MONDAY... 
Increasing high avalanche danger above 5000 feet and 
considerable below Sunday morning. High avalanche 
danger above 4000 feet and considerable below Sunday 
afternoon to Monday morning. Avalanche danger beginning 
to decrease Monday afternoon and night.


* MT HOOD AREA-
.AVALANCHE WARNING SUNDAY AND MONDAY... 
Increasing high avalanche danger below 7000 feet Sunday 
morning. Extreme avalanche danger above 5000 feet and 
high below Sunday afternoon to Monday morning. 
Avalanche danger beginning to decrease Monday afternoon 
and night.


SNOWPACK ANALYSIS

The general snow pack structure in most areas until 
yesterday should be something like about 1-2 feet of 
slightly consolidated snow from late November, over weak 
faceted snow from mid November, over shallow firmer snow 
or crusts from early in the season. A similar though 
shallower structure might be expected east of the crest.


Some good ski conditions but also some signs of 
instability were reported on Saturday on the Turns All 
Year, the FOAC web site, and by snow safety crews. Signs 
of instability such as easy clean shears and low 
Rutchblock scores were seen near Snoqualmie, Crystal and 
at Mt Hood Meadows.


Note that this snowpack structure is not expected to 
support the forecast heavy loads of snow and rain with a 
warming trend Sunday and Monday.


However terrain and vegetation are also indicated to be 
anchoring a shallow snowpack at lower elevations 
especially east of the Cascade crest. Note that 
avalanches that begin at higher elevations Sunday or 
Monday may run into run out zones with much less snow 
cover.


SUNDAY AND SUNDAY NIGHT

Increasing strong crest level winds, heavy snow and then 
possible rain and a warming trend is expected to begin on 
Sunday. This should cause an avalanche cycle to begin on 
Sunday. Widespread avalanches are fairly certain by late 
Sunday. Avalanches that begin in recent snow may step 
down to deeper layers. Deep 4-6 foot natural or human 
triggered avalanches are expected at higher elevations. 
Back country travel near avalanche terrain is not 
recommended on Sunday.


MONDAY AND MONDAY NIGHT

Continued very strong crest level winds, heavy snow or 
rain with high snow levels are expected on Monday. 
Natural or human triggered avalanches remain likely on 
Monday. Destructive avalanches will remain most possible 
on steep slopes that do not release on Sunday. Avalanches 
may stabilize other slopes. Back country travel near 
avalanche terrain is also not recommended on Monday. 
Avalanche danger may begin to decrease late Monday as 
snow or rain intensities decrease and temperatures cool 
and avalanches stabilize many slopes.


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