CHAMONIX VALLEY AND MONT-BLANC AREA WEATHER FORECAST


Tan Taïgi
Sweeping
And then not sweeping
The fallen leaves
ISSUED AT 08:15 THURSDAY OCTOBER 18
VALID FROM : THURSDAY OCTOBER 18 ‑‑ UNTIL : TUESDAY OCTOBER 23 2018

GENERAL SYNOPSIS
To the south or the Alpine Range, disturbed systems currently ruling over Western Mediterranean Basin and Iberia continue to drive humid air towards Pyrénées and Bay of Biscaye. To the northwest, the Azores High Ridge which already reaches British Isles will little by little rotate southeast : wind patterns are very light over Eastern France, yet with a temporary loose fœhn gradient today between Italian Piedmont and Savoy. • Fair weather already established, very mild with slightly hazy sunshine at times, will continue until Monday, or even improve if possible, while becoming gradually cooler with northeasterly winds above low stratus cloud patches which should not be toping above 800 to 1000 m.
TODAY - THURSDAY OCTOBER 18
Fair weather ‑ cool in the morning ‑ warm in the afternoon
SKY CONDITION : clear or partly cloudy ‑ some thin high cloud passings. Period of sunshine close to 90%.
PRECIPITATION : none.
WIND - ground level : NE with light fœhn trend ‑> variable light ‑> calm.
WIND - mid mountain : ENE ‑> SE light.
WIND - high mountain : NE ‑> E light.
TEMPERATURE : low +4°C - high +22°C - temperature inversion toward 1800 m early in the morning.
ISOTHERM 0°C : 3500 ‑> 3600 m.
ISOTHERM -10°C : 4900 ‑> 5200 m.
OVERNIGHT
Fair weather ‑ chilly in the valley ‑ fairly mild in the median altitude range
SKY CONDITION : clear or partly cloudy ‑ some thin high cloud passings at first.
PRECIPITATION : none.
WIND - aloft : E light.
TEMPERATURE : low +3°C - temperature inversion toward 1700 m.
FRIDAY OCTOBER 19
Amazingly fair weather ‑ unseasonably mild
SKY CONDITION : clear. Period of sunshine close to 100%.
PRECIPITATION : none.
WIND - aloft : E ‑> variable ‑> NW light.
TEMPERATURE : low +2 °C - high +22°C - temperature inversion toward 1700 m early in the morning.
SATURDAY OCTOBER 20
Amazingly fair weather ‑ unseasonably mild ‑ somewhat chilly NE wind high up
SKY CONDITION : clear. Period of sunshine close to 100%.
PRECIPITATION : none.
WIND - aloft : NE faible à modéré ‑> ENE modéré.
TEMPERATURE : steady.
EXTENDED OUTLOOK UNTIL TUESDAY OCTOBER 23 2018

Sunday and Monday : sunny ‑ somewhat cooler on the whole, yet still unseasonably mild. Tuesday and Wednesday : altitude polar air inflow towards Adriatic Sea, then Southern Tyrrhenian Sea, is expected to causing cloudy and cold weather, however dry with strong northeasterly winds high up.

Forecast reliability : fairly good until Saturday ‑ poor thereafter.

ReportsAs a reminder, today in Chamonix, the sun rises at 07:53:52 and goes down at 18:41:20.
45.55 N 6.51 E - Altitude 1040 m
October 18 07:00
Temperature +4°C
Relative humidity 88%
Wind 0 km/h
Sea level pressure 1016 hpa - rising slowly
Pressure at 1042 m 899 mb
Precipitation last 6h 0.0 mm
Skies clear
Visibility 75000 m
Altitude 3845 m
October 18 07:00
Temperature -3°C
Wind NE 10 km/h
Altitude 2250 m
October 18 06:00
Snow depth 0 cm
Wind 5 km/h
Gusts -- km/h
Temperature +7°C