CHAMONIX VALLEY AND MONT-BLANC AREA WEATHER FORECAST


Matsuo Bashō
Ah spring spring
How great is spring !
and so on
ISSUED AT 19:00 ON MONDAY APRIL 24, 2017
VALID FROM : MONDAY APRIL 24 -- UNTIL : SUNDAY APRIL 30 2017

GENERAL SYNOPSIS
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
Partly cloudy and mild, then cloudy with clear spells - increasing wind high up
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
Morning sunny spells - becoming cloudy with showers - strong wind high up
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.
Uncertain.
TUESDAY TO WEDNESDAY NIGHT - APRIL 25 TO 26
Bad weather - fairly heavy rain at times - strong wind high up
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.
Uncertain.
WEDNESDAY APRIL 26
Mainly cloudy and cold - wintry precipitation - strong wind high up
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.
Uncertain.
THURSDAY APRIL 27
Unsettled and cold ‑ scattered snow shower ‑ fleeting sunny spell ‑ strong wind high up
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.
Very uncertain.
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.

ReportsAs a reminder, today in Chamonix, the sun rises at 06:29:31 and goes down at 20:31:35.
45.55 N 6.51 E - Altitude 1040 m
24 April 07:00
Temperature 0°C
Relative humidity 73%
Wind 0 km/h
Sea level pressure 1016 hpa - steady
Pressure at 1042 m 900 mb
Precipitation last 6h 0.0 mm
Skies clear
Visibility 100000 m
Altitude 3845 m
24 April 07:00
Temperature -10°C
Wind WNW 30 km/h
Altitude 2250 m
24 April 06:00
Snow depth 75 cm
Wind 10 km/h
Gusts -- km/h
Temperature +2°C