CHAMONIX VALLEY AND MONT-BLANC AREA WEATHER FORECAST


Matsuo Bashō
In summer rain
The leg of the crane
Becomes shorter
ISSUED AT 18:15 ON FRIDAY JULY 31, 2015
VALID FROM : FRIDAY JULY 31 2015 -- UNTIL : THURSDAY AUGUST 06 2015

GENERAL SYNOPSIS
The Azores high ridge is weakening quickly over Northern France tonight, allowing for the Iberian / Western Mediterranean low area, to drive humid, warm and unsettled air towards the Alps, thus triggering a rainy-thundery spell over the area on Saturday. High cell expected to rebuilding from Central Europe while expanding towards the Alps on Saturday evening. Fine summer condition will be therefore resuming on Sunday and Monday. Thundery deterioration is to be considered on Tuesday afternoon, but this is still uncertain by now.
FRIDAY EVENING JULY 31 - AND OVERNIGHT
Cloudy to mainly cloudy - windy high up - becoming overcast - showers later
SKY CONDITION : in the evening and in the first part of the night, thick cloud patches crossing over - some clear spells at times - becoming overcast later.
PRECIPITATION : showers starting up towards the end of the night, moderate, with possible local thunderstorm - rain-snow limit towards 3500 m.
WIND - ground level : variable light.
WIND - mid mountain : SSW light to moderate.
WIND - high mountain : WSW moderate to strong -> SW moderate.
TEMPERATURE : low +11°C.
ISOTHERM 0°C : 3900 -> 3800 m.
ISOTHERM -10°C : 5500 -> 5400 m.
Uncertain.
ROAD CONDITION  : @ 06:30, dry roadways.morelive precipitation radar over the Alps
TOMORROW - SATURDAY AUGUST 01
Unsettled and cool ‑ thundery showers, mostly in the morning and in the evening
SKY CONDITION : mostly cloudy to overcast - possible fleeting sunny spells towards the middle of the day. period of sunshine close to 20%.
PRECIPITATION : thundery showers, light to moderate on the whole, yet heavier and more frequent early in the morning and towards the latter part of the afternoon - rain-snow limit towards 3400 m.
WIND - ground level : variable light.
WIND - mid mountain : SSW light to moderate -> variable light.
WIND - high mountain : SW moderate -> W light.
TEMPERATURE : low +11°C - high +20°C.
ISOTHERM 0°C : 3800 -> 3700 m.
ISOTHERM -10°C : 5400 -> 5600 m.
Uncertain.
SATURDAY TO SUNDAY NIGHT - AUGUST 01 TO 02
Mainly cloudy with showers at first, then clear spells spreading out
SKY CONDITION  : mostly cloudy - becoming cloudy with clear spells spreading out - probably clear or partly cloudy by dawn.
PRECIPITATION : scattered showers early in the night - rain-snow limit towards 3300 m - dry later.
WIND - aloft : W faible -> NW light to moderate.
TEMPERATURE : low +9°C.
Uncertain.
SUNDAY AUGUST 02
Fine summer condition resuming - hot in the afternoon
SKY CONDITION : clear or partly cloudy - afternoon cumulus cloud over the massifs. Period of sunshine close to 80%.
PRECIPITATION : none.
WIND - aloft : NW -> W light to moderate.
TEMPERATURE : low +9 °C - high +26°C.
Same kind of weather over the Upper Aosta Valley and the bordering Valais.
MONDAY AUGUST 03
Fine summer condition ‑ getting even hotter in the afternoon
SKY CONDITION : clear or partly cloudy. Period of sunshine close to 95%.
PRECIPITATION : none.
WIND - aloft : W light to moderate.
TEMPERATURE : low +9°C - high +30°C.
Same kind of weather over the Upper Aosta Valley and the bordering Valais.
EXTENDED OUTLOOK UNTIL THURSDAY AUGUST 06 2015

Tuesday : sunny morning ‑ large cumulus cloud growth in the afternoon, going along with intense heat ‑ evening thunderstorm likely. Wednesday and Thursday : sunny ‑ hot in the afternoon.

Forecast reliability : poor.

ReportsAs a reminder, today in Chamonix, the sun rises at 06:15:21 and goes down at 21:02:20.
45.55 N 6.51 E - Altitude 1040 m
31 July 07:00
Temperature +7°C
Relative humidity 85%
Wind 0 km/h
Sea level pressure 1016 hpa - falling slowly
Pressure at 1042 m 897 mb
Precipitation last 6h 0.0 mm
Skies clear
Visibility 75000 m
Altitude 3845 m
31 July 07:00
Temperature -3°C
Wind WSW 25 km/h
Altitude 2250 m
31 July 06:00
Snow depth 0 cm
Wind 5 km/h
Gusts -- km/h
Temperature +7°C