CHAMONIX VALLEY AND MONT-BLANC AREA WEATHER FORECAST


Takahama Kyoshi
The snake flees—
But the eyes that peered at me
Remain in the weeds
ISSUED AT 20:15 ON SATURDAY SEPTEMBER 24, 2016
VALID FROM : SATURDAY SEPTEMBER 24 -- UNTIL : FRIDAY SEPTEMBER 30 2016

GENERAL SYNOPSIS
Extended high 1022-1025 hpa, Alps to Black Sea and further to Baltic Lands, refocusing over the Eastern Scandinavian on Monday. • Fair weather overnight and on Sunday, with a tiny fœhn pattern tending towards warming up the atmosphere. • Broken cloud patches coming in from the west on Sunday evening. The high pressure shielding will indeed be temporarily knocked over by a weak thalweg linked to an Atlantic low moving in the vicinity of Iceland; pressure will increase again as soon as Tuesday morning. • Fairly changeable weather to be expected therefore on Monday, with a very light shower risk, probably; then improving fairly sunny on Tuesday.
SATURDAY EVENING SEPTEMBER 24 - AND OVERNIGHT
Fair night - somewhat cool in the lower part of the valley
SKY CONDITION : clear.
PRECIPITATION : none.
WIND - ground level : calm - at times light NE fœhn wind.
WIND - mid mountain : variable -> S light.
WIND - high mountain : ESE -> SSE light to moderate.
TEMPERATURE : low +7°C.
ISOTHERM 0°C : 3500 -> 3600 m.
ISOTHERM -10°C : 5100 -> 5200 m.
Partly cloudy along the Italian slopes.
TOMORROW - SUNDAY SEPTEMBER 25
Sunny - cool in the morning - unseasonably warm in the afternoon
SKY CONDITION : clear or partly cloudy - becoming cloudy from the west later in the evening. Period of sunshine close to 85%.
PRECIPITATION : none.
WIND - ground level : variable -> SW light.
WIND - mid mountain : S light -> SW light to moderate -> WSW light.
WIND - high mountain : SSE light to moderate -> SSW light.
TEMPERATURE : low +6°C - high +22°C.
ISOTHERM 0°C : 3600 -> 3300 m.
ISOTHERM -10°C : 5200 -> 5000 m.
Light fœhn wind puffs still possible in the morning.
SUNDAY TO MONDAY NIGHT - SEPTEMBER 25 TO 26
Cloudy deterioration - getting colder
SKY CONDITION  : cloudy - high cloud veiling the sky - broken cloud patches in the median altitude range.
PRECIPITATION : probably none.
WIND - aloft : SSW -> W light.
TEMPERATURE : low +8°C.
Same weather over the Upper Aosta Valley and the bordering Valais.
MONDAY SEPTEMBER 26
Changeable and cooler ‑ cloudy with fair sunny spells
SKY CONDITION : cloudy with sunny spells - mostly cloudy at times towards the evening. Period of sunshine close to 50%.
PRECIPITATION : very light shower riskin the afternoon - rain-snow limit towards 3000 m.
WIND - aloft : W light -> SW light to moderate.
TEMPERATURE : low +8 °C - high +19°C.
Incertain.
TUESDAY SEPTEMBER 27
Fairly sunny - little Bise wind high up
SKY CONDITION : early morning low cloud likely - else, partly cloudy - at times cloudy in the afternoon due to cumulus cloud growth. Period of sunshine close to 65%.
PRECIPITATION : none.
WIND - aloft : N -> NNE light to moderate - moderate at times.
TEMPERATURE : low +7°C - high +20°C.
Uncertain.
EXTENDED OUTLOOK UNTIL FRIDAY SEPTEMBER 30

Wednesday : fairly sunny ‑ cool in the morning ‑ mild in the afternoon ‑ fairly strong Bise wind high up in the morning. Thursday : fair weather likely, unseasonably mild, especially in the median altitude range. Friday : sunny - slightly cooler high up, thus somewhat unstable - increasing cloud in the afternoon.

Forecast reliability : good until Sunday - poor thereafter.

ReportsAs a reminder, today in Chamonix, the sun rises at 07:24:20 and goes down at 19:23:26.
45.55 N 6.51 E - Altitude 1040 m
25 September 07:00
Temperature +7°C
Relative humidity 83%
Wind 0 km/h
Sea level pressure 1022 hpa - rising slowly
Pressure at 1042 m 904 mb
Precipitation last 6h 0.0 mm
Skies clear
Visibility 80000 m
Altitude 3845 m
25 September 07:00
Temperature -4°C
Wind SSE 20 km/h
Altitude 2250 m
25 September 06:00
Snow depth 0 cm
Wind 5 km/h
Gusts 10 km/h
Temperature +4°C