Avalanche bulletin and weather forecast Haute Savoie

This avalanche translation of the Meteo France avalanche bulletin is produced mainly through an automated translation tool. Please use it in conjunction with the French bulletin found at the above link.

Bulletin issued Monday, December 10, 2007 at 16h06

N74101211
SNOW AND AVALANCHE BULLETIN - HAUTE SAVOIE
(VALID OFF MARKED AND OPEN TRAILS)
PREPARED ON MONDAY 10 DECEMBER
FOR TUESDAY 11 DECEMBER

ESTIMATE OF RISK UNTIL TUESDAY EVENING:
All Haute Savoie massives:
Higher than 2000 m: high risk (level 4) evolves to marked risk (level 3) Tuesday afternoon,
Lower than 2000 m: marked risk (level 3).

OVERVIEW OF WEATHER UNTIL TUESDAY EVENING:
The snowfall continues, then gradually returns to a lull Tuesday afternoon. Quantities expected between Monday evening and Tuesday noon: 20 to 30 cm.
Isotherme 0 DG: to 700 m.
Isotherme 10 DG: 2500 m.
Wind at 2000 m: North 20/40 km / h.
Wind at 4000 m: North 50 km / h.

SNOW CONDITIONS:
The snow cover is excellent for early December. The skiable limit is 1200 m on average, locally 1000 m on the Mont Blanc massif. Total snowfall this Tuesday morning: 40 to 70 cm at 1500 m, 1 m to 1.40 m to 2000 m.
Quality of snow on Tuesday: usually cold and deep snow. Areas exposed to altitude westerly winds are sometimes hard snow or more dense, heavy accumulations are likely sheltered in the garret.

STABILITY OF THE SNOW COVER: some large potential departures

At 2000 meters, the snow falling heavily for three days did not have time to stabilize. The average size of avalanches can go only then gaining momentum. Some large avalanches are possible during the snowfall, with aerosol in the event starting at high altitude or on large steep, slopes. All orientations are concerned, but especially in Northwest, North and East where the wind deposited heavy accumulations. Tuesday afternoon, with the end of the snowfall, the risk of spontaneous avalanches declines a little but releases are still possible with the passage of one or more skiers. Be wary especially in the areas of accumulation due to wind and proximity of slope failures.

At 2000 meters, the snow is based on a dense undercoat which had more or less stabilized after seeing the rain. Some medium-size avalanches are triggered and bring this snow surface, without taking real magnitude. The weight of a skier can help such a departure, in particular to the passage of a break in slope.

TREND FOR WEDNESDAY:
The risk decreases very slowly with the return of dry weather and an early settlement.

Météo updates this newsletter every day at 16h or earlier if conditions nivométéorologiques warrant.