CHAMONIX VALLEY AND MONT-BLANC AREA WEATHER FORECAST


Matsuo Bashō
On a mountain path
Something might charm you
A wild violet
ISSUED AT 18:55 ON SATURDAY SEPTEMBER 27, 2014
VALID FROM : SATURDAY SEPTEMBER 27 2014 -- UNTIL : FRIDAY OCTOBER 03 2014

GENERAL SYNOPSIS
High 1029 hpa over Austria, drifting over Hungary while reaching 1032 hpa towards the end of the night. It is driving a very mild air mass high up over the Alps until Monday. Current magnificent condition is expected to persisting until Sunday evening, while a southerly to southwesterly stream is due to setting up on Monday, slightly unsettled, although probably without precipitation in the valley due to a slight fœhn wind effect. Further outlook is still uncertain by now.
SATURDAY EVENING SEPTEMBER 27 - AND OVERNIGHT
Clear skies - almost cold in the valley by dawn
SKY CONDITION : clear - partly cloudy at times before dawn - thin high cloud.
PRECIPITATION : none.
WIND - ground level : variable light or nil.
WIND - mid mountain : mainly S - very light.
WIND - high mountain : variable -> S light.
TEMPERATURE : low +5°C.
ISOTHERM 0°C : 4300 -> 4000 m.
ISOTHERM -10°C : 5900 m.
Temperature inversion towards 1500 m. Slightly hazy over the Upper Aosta Valley towards the end of the night.
TOMORROW - SUNDAY SEPTEMBER 28
Sunny - cool in the morning - very mild or warm at times in the afternoon
SKY CONDITION : clear in the morning - partly cloudy in the afternoon - high cloud. period of sunshine close to 85%.
PRECIPITATION : none.
WIND - ground level : variable light or nil in the morning - light to moderate thermal breeze early in the afternoon.
WIND - mid mountain : mainly S - very light.
WIND - high mountain : S light -> SSW light to moderate.
TEMPERATURE : low +5°C - high +24°C.
ISOTHERM 0°C : 4000 -> 3800 m.
ISOTHERM -10°C : 5900 m.
Afternoon fœhn wind puffs likely in the valley.
SUNDAY TO MONDAY NIGHT - SEPTEMBER 28 TO 29
Clear at first - becoming cloudy by the end of the night
SKY CONDITION  : clear or partly cloudy - becoming partly cloudy, then cloudy towards the latter part of the night - thickening high cloud.
PRECIPITATION : none.
WIND - aloft : SSW light to moderate - moderate at times.
TEMPERATURE : low +8°C.
Light fœhn wind in the valley. More cloud in the Upper Aosta Valley.
MONDAY SEPTEMBER 29
Mild and dry ‑ thick hazy skies ‑ light fœhn wind likely
SKY CONDITION : cloudy - thick high cloud running over from the south. Period of sunshine close to 50%.
PRECIPITATION : none.
WIND - aloft : SSW light to moderate -> moderate.
TEMPERATURE : low +8 °C - high +21°C.
Light fœhn wind likely in the valley. Uncertain.
TUESDAY SEPTEMBER 30
Cloud patches crossing over from the southwest ‑ afternoon shower risk
SKY CONDITION : mostly cloudy - at times cloudy with sunny spells. Period of sunshine close to 35%.
PRECIPITATION : afternoon shower risk - rain-snow limit towards 3400 m, dropping.
WIND - aloft : SW moderate - light to moderate at times.
TEMPERATURE : low +9°C - high +19°C.
Very uncertain.
EXTENDED OUTLOOK UNTIL FRIDAY OCTOBER 3

Wednesday : cloud patches crossing over from the west with showers. Thursday and Friday: fairly sunny - somewhat milder than seasonal average. Very uncertain during the three days.

Forecast reliability : fairly good until Sunday ‑ poor thereafter.

ReportsAs a reminder, today in Chamonix, the sun rises at 07:30:02 and goes down at 19:14:44.
45.55 N 6.51 E - Altitude 1040 m
30 September 08:00
Temperature +11°C
Relative humidity 95%
Wind 0 km/h
Sea level pressure 1027 hpa - falling slowly
Pressure at 1042 m 908 mb
Precipitation last 6h 0.0 mm
Skies mostly cloudy
Visibility 20000 m
Altitude 3845 m
30 September 08:00
Temperature -1°C
Wind SSW 15 km/h
Altitude 2250 m
30 September 08:00
Snow depth 0 cm
Wind 5 km/h
Gusts -- km/h
Temperature +7°C