CHAMONIX VALLEY AND MONT-BLANC AREA WEATHER FORECAST


Tan Taïgi
Sweeping up
And then not –
Fallen leaves –
ISSUED AT 10:10 SATURDAY DECEMBER 03 2022
VALID : SATURDAY 03 -- THURSDAY DECEMBER 08 2022

GENERAL SYNOPSIS
Powerful high, NW Siberia (> 1050 hpa) up to N Scotland on one hand (> 1030), and up to South-Tyrol on the other (≥ 1022). • Weakening pressure field along the Alpine Range (Sallanches, 1015 - Sion, 1014 - Innsbruck, 1017) in the fringes of an extended low area towards 1005 hpa between Gibraltar and Sardinia. • This mediterranean minimum is linked to some Altitude cut-off towards SW France (Bordeaux-Aurillac), which should subside overnight, but until then will contribute to a moderate foehn gradient between Savoie and Italian Piedmont. • Resulting flow in the valley shall be dry and quite gusty, likely to reach 50-60 km/h towards Les Praz. • In the Aosta Valley, uphill proceeding of mediterranean humidity is likely to trigger light to moderate snowfall above 1700 m. Some overflow, Italy->France, may probably occur over the bordering ridge
TODAY - SATURDAY DECEMBER 03
Mainly cloudy - remaining dry owing to foehn - windchill increases cold feeling
SKY CONDITION : mainly cloudy to overcast, changeable ceiling between 3500 et 3700 m - fleeting sunny spell cannot be ruled out, towards noon or so. Period of sunshine close to 15%.
PRECIPITATION : none in the valley - windblown snow towards italian bordering ridge.
WIND - ground level : foehny NE moderate - occasionally and locally fairly strong.
WIND - mid mountain : SSE by SE moderate to strong - occasionally moderate.
WIND - high mountain : S moderate to strong - occasionally strong -> decreasing moderate towards evening.
TEMPERATURE : low +2°C - high +5°C.
ISOTHERM 0°C : 1800 -> 2100 m.
ISOTHERM -10°C : 3000 -> 3500 m.
OVERNIGHT
Mainly cloudy, yet dry - decreasing wind, any altitude - seasonable temperature
SKY CONDITION : persistent broken cloud layer, median and high altitude range - iso 0°C towards 2000 m.
PRECIPITATION : none.
WIND - aloft : SSE -> S moderate - locally moderate to strong at times.
TEMPERATURE : low +1°C.
SUNDAY DECEMBER 04
Gloomy - rainy-snowy deterioration likely, still uncertain, probably in the afternoon
SKY CONDITION : persistent changeable cloud layer in the median altitude range - thickening cloud running over from S in the afternoon. Period of sunshine close to 5%.
PRECIPITATION : showery, running over from S - rain-snow limit stabilizing towards 1000 m in the afternoon - not much - turning into snowfall, light yet continuous in the first part of following night (4-8 cm towards 1500 m).
WIND - aloft : S moderate, gusty.
TEMPERATURE : low 0 °C - high +6°C.
MONDAY DECEMBER 05
Mainly cloudy early in the morning - sunny spells probably spreading thereafter
SKY CONDITION : mostly cloudy early in the morning - becoming cloudy with sunny spells, more widespread in the afternoon. Period of sunshine close to 45%.
PRECIPITATION : remaining light shower from the night not unlikely towards daybreak - else none.
WIND - aloft : mainly S, light to moderate, occasionally moderate -> variable or W light.
TEMPERATURE : dropping lows.
EXTENDED OUTLOOK UNTIL THURSDAY DECEMBER 08

Tuesday : fairly sunny after some early morning low cloud or fog patches dispelling - bitter cold (-6°C) in the valley by daybreak - yet rather mild on sunny slopes later. Wednesday : very uncertain - disturbance likely to crossing over the area - light precipitation in the afternoon, rain-snow limit towards Chamonix. Thursday : very uncertain in the tail of previous night's disturbance, still some snow shower in the valley.

Forecast reliability : fairly good until Sunday - poor thereafter.

ReportsAs a reminder, today in Chamonix, the sun rises at 07:57:26 and goes down at 16:48:19.
Chamonix - ville
45.55 N 6.51 E - Altitude 1030 m
December 02, 2022 08:00
Temperature +3.2°C
Relative humidity 67%
Wind NE 10-60 km/h
Sea level pressure 1014 hpa - falling slowly
Pressure at 1042 m 893 mb
Precipitation last 6h 0 mm
Skies overcast - ceiling 3500 m
Visibility 10 000 m
Altitude 3845 m
December 02, 2022 08:00
Temperature -16°C
Wind NW 15-85 km/h
Altitude 2250 m
December 02, 2022 08:00
Snow depth 63 cm
Wind NNE 10 km/h
Gusts W 25 km/h
Temperature -4.1°C