CHAMONIX VALLEY AND MONT-BLANC AREA WEATHER FORECAST


Sōma Senshi
Particle
In the winter sun
I d'like to leave
ISSUED AT 19:15 ON FRIDAY NOVEMBER 17, 2017
VALID FROM : FRIDAY NOVEMBER 17 -- UNTIL : THURSDAY NOVEMBER 23 2017

GENERAL SYNOPSIS
High, 1029 hpa Southern Ireland to Brittany, refocusing towards 1027 hpa over the Bay of Biscaye on Saturday. • Deep low 975 hpa, Norwegian Sea, filling slightly while moving towards Southern Scandinavia by the same time. • Northwesterly stream is due to increasing between both areas of opposite action; it will veer north-northwest by Saturday evening and propel polar air up to the Adriatic Sea by Sunday evening. • Resulting cold front, not much active over the Western Alps, will be triggering light snowfall in the valley towards Sunday morning. • Further outlook, although uncertain, allows to consider some improvement on Monday, depending on a high pressure increase over Southwestern France, then a new deterioration from the north on Tuesday.
FRIDAY EVENING NOVEMBER 17 - AND OVERNIGHT
Skies expected to stay mostly clear - very cold in the valley
SKY CONDITION : still some high cloud passings at first, then skies will clear above persisting fog patches towards 1100-1200 m.
PRECIPITATION : none.
WIND - ground level : calm.
WIND - mid mountain : NE light.
WIND - high mountain : NW light to moderate -> NNW moderate.
TEMPERATURE : low -8°C.
ISOTHERM 0°C : 2400 -> 2200 m.
ISOTHERM -10°C : 4000 -> 3900 m.
Thicker and lasting cloud in Valais. Milder in the Italian Upper Valleys.
ROAD CONDITION  : @ 16:00, dry roadways on the whole. Black ice risk in foggy areas.morelive precipitation radar over the Alps
TOMORROW - SATURDAY NOVEMBER 18
Sunny - very cold in the morning - milder afternoon - becoming windy high up
SKY CONDITION : clear or partly cloudy - thin high cloud coming in towards the latter part of the afternoon - fog patches likely to persisting below 1100 m in the morning. Period of sunshine close to 90%.
PRECIPITATION : none.
WIND - ground level : calm - SW very light at times.
WIND - mid mountain : NE light.
WIND - high mountain : NNW moderate -> moderate to strong.
TEMPERATURE : low -8°C - high +4°C.
ISOTHERM 0°C : 2200 -> 1900 -> 2000 m.
ISOTHERM -10°C : 3900 -> 3800 m.
Same kind of weather in the bordering Valais. Milder in the Italian Upper Valleys.
SATURDAY TO SUNDAY NIGHT - NOVEMBER 18 TO 19
Cloudy deterioration - very cold with strong wind high up
SKY CONDITION  : partly cloudy - becoming mostly cloudy from the north.
PRECIPITATION : probably none until dawn.
WIND - aloft : NNW moderate to strong -> strong.
TEMPERATURE : low -4°C.
Uncertain.
SUNDAY NOVEMBER 19
Mostly cloudy - snow showers likely - gale high up
SKY CONDITION : mostly cloudy to overcast - fleeting sunny spells likely in the afternoon. Period of sunshine close to 25%.
PRECIPITATION : intermittent and light, mostly in the morning - rain-snow limit towards 700 m, rising up towards 1000 m - ± 5 cm at 1500 m.
WIND - aloft : NNW strong - gale at times.
TEMPERATURE : low -5 °C - high +2°C.
Uncertain.
MONDAY NOVEMBER 20
Cold and cloudy with sunny spells ‑ dry ‑ windy high up
SKY CONDITION : fair sunny spells in the morning - thickening and more frequent cloud passings in the afternoon. Period of sunshine close to 45%.
PRECIPITATION : none.
WIND - aloft : NNW -> WNW moderate to strong.
TEMPERATURE : low -7°C - high +6°C.
Uncertain.
EXTENDED OUTLOOK UNTIL THU. NOVEMBER 23

Tuesday : mainly cloudy ‑ wintry shower likely. Wednesday : improving temporarily ‑ fairly sunny ‑ getting noticeably milder. Thursday : mostly cloudy, yet without chill - rain shower likely in the morning. Very uncertain for the three days.

Forecast reliability : poor.

ReportsAs a reminder, today in Chamonix, the sun rises at 07:36:23 and goes down at 16:58:49.
45.55 N 6.51 E - Altitude 1040 m
November 17 07:00
Temperature -4°C
Relative humidity 97%
Wind 0 km/h
Sea level pressure 1020 hpa - rising slowly
Pressure at 1042 m 902 mb
Precipitation last 6h 0.0 mm
Skies clear - fog patches - sw down in the valley
Visibility 120000 m
Altitude 3845 m
November 17 07:00
Temperature -8°C
Wind N 25 km/h
Altitude 2250 m
November 17 06:00
Snow depth 10 cm
Wind 10 km/h
Gusts 20 km/h
Temperature +2°C