CHAMONIX VALLEY AND MONT-BLANC AREA WEATHER FORECAST


Natsume Sôseki
Ask the breeze
Which leaf
First to fall will be
ISSUED AT 08:45 SUNDAY OCTOBER 13
VALID FROM : SUNDAY OCTOBER 13 ‑‑ UNTIL : FRIDAY OCTOBER 18 2019

GENERAL SYNOPSIS
Moderate to strong southwest stream between low pressure area approaching British Isles and high pressure field over the Central Mediterranean, that is linked to some African altitude high pressure component. • Tiny relative minimum south of Balearic Islands is still currently driving altitude humid puffs towards the Alps, this Sunday morning. • Moreover, moderate foehn gradient (+6 hpa) will get tighter for a while in the afternoon between Savoie and Italian Piedmont, then again between Monday evening and Tuesday morning, preceding fairly active disturbance crossing over our Region on Tuesday.
TODAY - SUNDAY OCTOBER 13
Fair weather ‑ warm with some fœhn in the afternoon ‑ windy high up
SKY CONDITION : partly cloudy to cloudy, then clear ‑ still some high cloud patches from southwest early in the morning, 5000‑6000 m. Period of sunshine close to 85%.
PRECIPITATION : none.
WIND - ground level : variable light ‑ light to moderate foehn spreading from the upper valley.
WIND - mid mountain : SW moderate ‑ slightly stronger gusts towards the middle of the day.
WIND - high mountain : SW moderate to strong ‑> moderate towards the evening.
TEMPERATURE : low +6°C - high +24°C.
ISOTHERM 0°C : 3600 ‑> 3500 ‑> 3700 m.
ISOTHERM -10°C : 5100 m.
OVERNIGHT
Fair weather, unseasonably mild ‑ fœhn in the valley
SKY CONDITION : clear or partly cloudy ‑ snow surface re‑freezing : fairly good radiation condition, french slopes, iso 0°C towards 3700 m.
PRECIPITATION : none.
WIND - aloft : SW ‑> SSW moderate ‑ light foehn in the valley.
TEMPERATURE : low +8°C.
MONDAY OCTOBER 14
Sunny ‑ warm in the afternoon ‑ increasing foehn over the hours
SKY CONDITION : clear or partly cloudy. Period of sunshine close to 90%.
PRECIPITATION : none.
WIND - aloft : SSW moderate ‑> moderate ‑ gusty fœhn in the valley.
TEMPERATURE : low +7 °C - high +24°C.
TUESDAY OCTOBER 15
Decreasing foehn early in the morning, then active cold front crossing ‑ windy
SKY CONDITION : cloudy in the morning ‑ thick high cloud with fleeting veiled early in the morning ‑ becoming mostly cloudy to overcast. Period of sunshine close to 15%.
PRECIPITATION : probably starting up early in the morning, light ‑ becoming moderate by the middle of the day ‑ getting lighter in the evening ‑ rain‑snow limit towards 2800 m, dropping towards 2000 m ‑ expected water in the valley : 15‑30 mm.
WIND - aloft : S moderate to strong ‑> W moderate ‑ foehn moderate to strong in the valley, dropping soon.
TEMPERATURE : .
EXTENDED OUTLOOK UNTIL FRIDAY OCTOBER 18 2019

Wednesday and Thursday : uncertain ‑ fairly sunny ‑ almost warm in the afternoon with some convection. Friday : very uncertain ‑ cloudy deterioration likely upon approach of frontal disturbance. • Westerly stream backing southwest, moderate on the whole during the three days.

Forecast reliability : fairly good until Monday.

ReportsAs a reminder, today in Chamonix, the sun rises at 07:46:46 and goes down at 18:50:40.
45.55 N 6.51 E - Altitude 1040 m
October 13 07:00
Temperature +6°C
Relative humidity 89%
Wind 0 km/h
Sea level pressure 1019 hpa - steady
Pressure at 1042 m 902 mb
Precipitation last 6h 0.0 mm
Skies cloudy - high cloud patches running over from south
Visibility 60000 m
Altitude 3845 m
October 13 07:00
Temperature -2°C
Wind SW 50 km/h
Altitude 2250 m
October 13 06:00
Snow depth 0 cm
Wind 20 km/h
Gusts 25 km/h
Temperature +10°C