CHAMONIX VALLEY AND MONT-BLANC AREA WEATHER FORECAST


Matsuo Bashō
In summer rain
The leg of the crane
Becomes shorter
ISSUED AT 20:10 ON MONDAY AUGUST 03, 2015
VALID FROM : MONDAY AUGUST 03 -- UNTIL : SUNDAY AUGUST 09 2015

GENERAL SYNOPSIS
Low 985 hpa, northwest of Ireland, moving northeast and driving a light to moderate southwesterly stream over France and the Alps. Linked disturbance will drive thundery showers or thunderstorms against the Western Alps towards Tuesday noon, then will move away eastward while disintegrating later in the afternoon because of a slight pressure rise over the Alps going along with a warm african air income from the southwest high up. Resuming summer hot condition from Wednesday until Friday, ahead of a thundery deterioration on Saturday.
MONDAY EVENING AUGUST 03 - AND OVERNIGHT
Clear skies at first - becoming hazy later - windy high up
SKY CONDITION : clear until the latter part of the night - fairly thick high cloud coming in from the west shortly before dawn.
PRECIPITATION : none.
WIND - ground level : variable light.
WIND - mid mountain : WSW light -> SSW light to moderate.
WIND - high mountain : W light to moderate -> SW moderate to strong.
TEMPERATURE : low +13°C.
ISOTHERM 0°C : 4600 -> 4400 m.
ISOTHERM -10°C : 6100 -> 5800 m.
Same kind of weather over the Upper Aosta Valley and the bordering Valais, slightly delayed.
ROAD CONDITION  : @ 06:30, dry roadways.morelive precipitation radar over the Alps
TOMORROW - TUESDAY AUGUST 04
Unsettled ‑ thundery disturbance crossing over - improving later
SKY CONDITION : cloudy early in the morning - thickening high cloud - fat cumulus cloud growth - clear spells spreading out in the evening. period of sunshine close to 45%.
PRECIPITATION : thundery showers or thunderstorms passing towards the middle of the day - rain-snow limit towards 4000 m.
WIND - ground level : variable light to moderate - possible thunderstorm gust.
WIND - mid mountain : SSW light to moderate -> SW light.
WIND - high mountain : SW moderate to strong -> W moderate.
TEMPERATURE : low +13°C - high +22°C.
ISOTHERM 0°C : 4400 -> 4200 -> 4500 m.
ISOTHERM -10°C : 5800 -> 6100 m.
Thunderstorm might be locally fairly strong. Uncertain.
TUESDAY TO WEDNESDAY NIGHT - AUGUST 04 TO 05
Cloud dispelling - clear and somewhat cool by dawn
SKY CONDITION  : cloudy with clear spells - becoming clear or partly cloudy.
PRECIPITATION : none.
WIND - aloft : W moderate -> light to moderate.
TEMPERATURE : low +11°C.
Incertain.
WEDNESDAY AUGUST 05
Fine summer weather - mild in the morning - hot in the afternoon
SKY CONDITION : clear or partly cloudy - some cumulus cloud over the massifs in the afternoon. Period of sunshine close to 95%.
PRECIPITATION : none.
WIND - aloft : W -> WSW light to moderate.
TEMPERATURE : low +11 °C - high +28°C.
Uncertain.
THURSDAY AUGUST 06
Fine summer weather ‑ hot in the afternoon with cumulus cloud over the massifs
SKY CONDITION : clear or partly cloudy - locally cloudy in the afternoon due to cumulus cloud growth. Period of sunshine close to 90%.
PRECIPITATION : late afternoon shower slight risk.
WIND - aloft : SW light to moderate.
TEMPERATURE : low +13°C - high +29°C.
Uncertain.
EXTENDED OUTLOOK UNTIL SUNDAY AUGUST 09 2015

Friday : sunny ‑ scorching heat ‑ evening thunderstorm likely. Satueday : unsettled and sultry - afternoon thunderstorm. Sunday : keeping on unsettled with thunderstorm risk - somewhat cooler.

Forecast reliability : poor in the short run ‑ better speaking of Wednesday and Thursday.

ReportsAs a reminder, today in Chamonix, the sun rises at 06:18:56 and goes down at 20:58:17.
45.55 N 6.51 E - Altitude 1040 m
4 August 07:00
Temperature +13°C
Relative humidity 90%
Wind 0 km/h
Sea level pressure 1020 hpa - steady
Pressure at 1042 m 900 mb
Precipitation last 6h 0.0 mm
Skies partly cloudy
Visibility 45000 m
Altitude 3845 m
4 August 07:00
Temperature +3°C
Wind WSW 40 km/h
Altitude 2250 m
4 August 06:00
Snow depth 0 cm
Wind 20 km/h
Gusts 40 km/h
Temperature +15°C