CHAMONIX VALLEY AND MONT-BLANC AREA WEATHER FORECAST
ISSUED AT 19:05 ON MONDAY FEBRUARY 27, 2017
VALID FROM : MONDAY FEBRUARY 27 2017 -- UNTIL : SUNDAY MARCH 05 2017
A mountain village
Under the piled-up snow
The sound of water
Very deep, extended and complex low system whirling around Scotland with a minimum 970 hpa toward Faroes; it contributes to a fœhn wind gradient along the high massifs with the remaining fairly high pressure field over Northern Italy, which will resolve in the first part of the night. • The cold front linked to that low system will be reaching our region towards the latter part of the night, triggering moderate precipitation or fairly heavy at times, allowing for snow in the valley by Tuesday evening, and causing a severe westerly gale high up as well. • Further outlook, still uncertain in detail, shows a series of westerly disturbances following each other until the first days of next week.
MONDAY EVENING FEBRUARY 27 - AND OVERNIGHT
SKY CONDITION : becoming cloudy in the first part of the night - thickening high cloud - overcast towards the middle of the night.
PRECIPITATION : starting up toward the latter part of the night - moderate, then fairly strong at times before dawn - rain-snow limit towards 1500 m, dropping - expected snowfall towards 1800 m : 10-20 cm, windblown.
WIND - ground level : variable light to moderate with fœhn wind puffs -> SW light.
WIND - mid mountain : SW moderate - WSW strong at times.
WIND - high mountain : SW strong -> WSW strong to gale force.
TEMPERATURE : low +3°C.
ISOTHERM 0°C : 1900 -> 1700 m.
ISOTHERM -10°C : 3600 -> 3300 m.
Uncertain, swift evolving phenomenon.
ROAD CONDITION ••••• : @ 16:00, roadways becoming snow covered above 1000 m.
TOMORROW - TUESDAY FEBRUARY 28
SKY CONDITION : overcast. Period of sunshine close to 0%.
PRECIPITATION : moderate on the whole - light and scattered towards the middle of the day - fairly strong at times in the afternoon - rain-snow limit dropping towards 1000 m - expected snowfall towards 1800 m : 20-30 cm, windblown.
WIND - ground level : SW light - moderate at times.
WIND - mid mountain : SW moderate -> WSW moderate to strong - strong at times.
WIND - high mountain : WSW strong to gale force -> moderate to strong.
TEMPERATURE : low +2°C - high +5°C.
ISOTHERM 0°C : 1700 -> 1200 m.
ISOTHERM -10°C : 3300 -> 2400 m.
Uncertain, swift evolving phenomenon.
TUESDAY TO WEDNESDAY NIGHT - MARCH 28 TO 01
SKY CONDITION : mostly cloudy to overcast.
PRECIPITATION : eventually fairly strong at first - becoming light to moderate - rain-snow limit towards 800 m - expected snowfall towards 1800 m : 15-25 cm, windblown.
WIND - aloft : WSW moderate to strong -> WNW strong.
TEMPERATURE : low -2°C.
WEDNESDAY MARCH 01
SKY CONDITION : mostly cloudy in the morning and towards the latter part of the afternoon - some fleeting sunny spells in the mean time. Period of sunshine close to 20%.
PRECIPITATION : scattered snow showers in the morning - scattered rain showers in the afternoon - rain-snow limit rising up towards 1500 m - expected snowfall towards 1800 m : ± 5 cm, windblown.
WIND - aloft : WNW strong -> NW gale -> WNW moderate to strong.
TEMPERATURE : low -2 °C - high +3°C.
THURSDAY MARCH 02
SKY CONDITION : mostly cloudy - becoming cloudy with sunny spells. Period of sunshine close to 40%.
PRECIPITATION : shower risk in the morning.
WIND - aloft : W moderate to strong -> moderate.
TEMPERATURE : low +2°C - high +8°C.
EXTENDED OUTLOOK UNTIL SUNDAY MARCH 05
Friday : cloudy with fair sunny spells ‑ dry ‑ unseasonably mild ‑ altitude flow backing south-southwest, strong high up ‑ fœhn wind getting up and possibly becoming strong towards the evening. Saturday : fairly weak disturbance crossing over in a fairly strong southwesterly high up. Sunday : changeable and colder - fleeting sunny spells - showers, may be snowy in the valley.
Forecast reliability : poor.
Considerable avalanche risk (3/5) above 1700 m.