CHAMONIX VALLEY AND MONT-BLANC AREA WEATHER FORECAST
ISSUED AT 19:00 ON MONDAY APRIL 24, 2017
VALID FROM : MONDAY APRIL 24 -- UNTIL : SUNDAY APRIL 30 2017
Ah spring spring
How great is spring !
and so on
Deepening low towards 990 hpa tonight over Southern Scandinavia. Pressure field sagging over France, especially Pyrénées to Alps where it is getting somewhat on the low side. • As a result over the Western Alps, altitude stream is backing southwest and will become strong by Tuesday afternoon. • Atmosphere should remain fairly mild during the main part of the night, thanks to a light fœhn gradient with the remaining high pressure field over Northern Italy and to increasing cloud passings from the southwest as well. • Some isolated pre-frontal showers might break out over our Region on Tuesday afternoon, ahead of a twofold cold front which is expected to crossing over during the Tuesday to Wednesday night, then on Wednesday, driven by a very unsettled polar air inflow over France : heavy precipitation likely on Wednesday morning; possible low altitude snowfall at times from Wednesday evening.
MONDAY EVENING APRIL 24 - AND OVERNIGHT
SKY CONDITION : partly cloudy to cloudy - cloud passings becoming thicker and more frequent towards the latter part of the night.
PRECIPITATION : none.
WIND - ground level : fœhn wind puffs -> calm -> SW light.
WIND - mid mountain : SW moderate -> moderate to strong.
WIND - high mountain : W light to moderate -> WSW moderate to strong.
TEMPERATURE : low +6°C.
ISOTHERM 0°C : 2600 -> 2400 m.
ISOTHERM -10°C : 4100 m.
Same kind of weather in the bordering Valais and the Upper Aosta Valley.
TOMORROW - TUESDAY APRIL 25
SKY CONDITION : cloudy with fair sunny spells at first in the morning - becoming mostly cloudy from the west-southwest - overcast in the evening. Period of sunshine close to 25%.
PRECIPITATION : starting up in the afternoon as light to moderate showers - rain-snow limit towards 2300 m, dropping towards the evening.
WIND - ground level : SW light.
WIND - mid mountain : SW moderate to strong -> moderate.
WIND - high mountain : WSW moderate to strong -> SW strong.
TEMPERATURE : low +4°C - high +15°C.
ISOTHERM 0°C : 2400 -> 2700 -> 2500 m.
ISOTHERM -10°C : 4100 m.
TUESDAY TO WEDNESDAY NIGHT - APRIL 25 TO 26
SKY CONDITION : mostly cloudy to overcast.
PRECIPITATION : becoming continuous and moderate in the first part of the night - fairly heavy at times later - rain-snow limit towards 2000 m, dropping towards 1500 m during the night - expected snowfall towards 2000 m : 15-25 cm, windblown.
WIND - aloft : SW strong - gusty.
TEMPERATURE : low +3°C.
WEDNESDAY APRIL 26
SKY CONDITION : overcast, then mostly cloudy - fleeting sunny spells likely in the afternoon. Period of sunshine close to 10%.
PRECIPITATION : moderate to heavy in the morning, turning into scattered showers in the afternoon - rain-snow limit dropping towards 1200 m - expected snowfall towards 2000 m : 10-20 cm, windblown.
WIND - aloft : SW -> WSW strong.
TEMPERATURE : low +1 °C - high +8°C.
THURSDAY APRIL 27
SKY CONDITION : mostly cloudy on the whole - fleeting sunny spells in the afternoon. Period of sunshine close to 15%.
PRECIPITATION : light isolated shower - rain-snow limit towards 800 m.
WIND - aloft : WSW strong.
TEMPERATURE : low 0°C - high +9°C.
EXTENDED OUTLOOK UNTIL SUNDAY APRIL 30
Friday : improving slightly ‑ some sunny spells ‑ shower risk ‑ getting slightly milder. Saturday : fairly sunny ‑ very cold in the morning ‑ fairly strong north wind high up. Sunday : fairly sunny - milder - becoming cloudy from the west during the afternoon.
Forecast reliability : poor.