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  INSTITUTE FOR SNOW AND AVALANCHE RESEARCH  DAVOS
               NATIONAL AVALANCHE BULLETIN NO. 66
                for Sunday, 13 January 2008
             issue date 12.1.2008, 18:30 hours
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  HIGH AVALANCHE DANGER REGIONALLY
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CURRENT CONDITIONS

On Saturday it snowed heavily down to low altitudes in southern 
regions and in the eastern part of the northern flank of the 
Alps. On the Main Alpine Ridge from Zermatt to Bergell and south 
thereof there was 50 to 70 cm of snowfall. In the region 
extending from the central and eastern parts of the northern 
flank of the Alps over central Grisons to the Upper Engadine, 
there was 20 to 40 cm of snow, elsewhere 10 to 20 cm. Midday 
temperatures at 2000 m were minus 6 degrees in northern regions 
and minus 4 degrees in southern regions. Stormy southerly winds 
prevailed to begin with, then slackened off and shifted to 
northerly. 
The new snow and the snowdrift are often poorly bonded with the 
old snowpack. Particularly on the Main Alpine Ridge from the 
Matterhorn to the Engadine and in Grisons, moreover, the snow 
overlays a weak old snowpack.


SHORT-TERM DEVELOPMENT

By Sunday morning another 10 to 15 cm of snow is expected in the 
Engadine, elsewhere there will be less. During the day it will 
turn increasingly sunny from the west. Midday temperatures at 
2000 m will be between minus 3 degrees in the northwest and 
minus 6 degrees in the southeast. Light to moderate northerly 
winds will shift to easterly, then southerly, during the night 
they will be strong in eastern regions. 
As the heavy precipitation comes to an end, natural avalanches 
will diminish. New snow and snowdrift will nevertheless remain 
highly trigger-sensitive to begin with.


AVALANCHE DANGER FORECAST FOR SUNDAY

Main Alpine Ridge from the Matterhorn to the Bernina; northern 
and central Ticino; Calanca valley; Misox; southern 
Surselva; Schams; Oberhalbstein and St. Moritz:
  High avalanche danger (Level 4)
The avalanche prone locations are found on steep slopes in 
all aspects above approximately 1500 m. Particularly during 
the night, natural avalanches are expected which can forge 
their way to the valley floors. Exposed sectors of 
transportation will then be put at risk widespread. In 
outlying terrain away from secured ski runs, highly critical 
conditions for backcountry skiers and freeriders prevail.

Remaining regions of the Swiss Alps:
  Considerable avalanche danger (Level 3)
On the remaining northern flank of the Alps east of the 
Reuss, in the remaining regions of Grisons and in Sotto 
Ceneri, the avalanche prone locations are found on steep 
slopes in all aspects above approximately 1800 m. During the 
night in particular, small to medium sized, as well as 
isolated large sized natural avalanches are expected. 
Isolated exposed sectors of transportation routes are 
endangered. 
On the remaining northern flank of the Alps west of the Reuss 
and in the remaining Valais, the avalanche prone locations 
are found on steep slopes in all aspects above approximately 
2000 m. There is little expectation of natural avalanches. 
In all regions of this danger level, even single backcountry 
skiers and freeriders can easily trigger avalanches. 
Extensive experience in assessing avalanche dangers, as well 
as great caution, are essential.


TREND FOR MONDAY AND TUESDAY

On Monday it will be quite sunny in northern regions, amid foehn 
winds. In southern regions as well as in the west in the 
afternoon, some snowfall is expected. Moderate to strong 
southwesterly winds will prevail. On Tuesday it will be 
variable. The avalanche danger will gradually subside.