CHAMONIX VALLEY AND MONT-BLANC AREA WEATHER FORECAST


Matsuo Bashō
Heat shimmer
Rising from the shoulder
My paper robe
ISSUED AT 13:00 ON SATURDAY JULY 04, 2015
VALID FROM : SATURDAY JULY 04 -- UNTIL : FRIDAY JULY 10 2015

GENERAL SYNOPSIS
High ridge 1020-1022 hpa, Spain to Western Russia, linked to an unusually hot air mass high up, weakening while a low system is approaching the British Isles from the west. Sun and scorching heat are ruling the Alps. Temperature highs, more than ten degrees above seasonal averages, are getting close to the 37.2°C record of July 1983. Heat thunderstorm risk, very low tonight, is expected to increasing on Sunday evening and during the following night. Very low again on Monday, it should be noticeably higher on Tuesday evening, preceding the cold front of the mentioned low which should have reached the North Sea by then. Actual activity of this cold front is still difficult to figure out for now.
SATURDAY EVENING JULY 04 - AND OVERNIGHT
Skies clearing quickly - very dry - almost warm
SKY CONDITION : partly cloudy, then clear.
PRECIPITATION : none.
WIND - ground level : variable light.
WIND - mid mountain : variable light.
WIND - high mountain : W light to moderate -> moderate.
TEMPERATURE : low +18°C.
ISOTHERM 0°C : 4600 m.
ISOTHERM -10°C : 5900 -> 5800 m.
Small isolated thunderstorm in the Aosta Valley towards the evening.
ROAD CONDITION  : @ 06:30, dry roadways.morelive precipitation radar over the Alps
TOMORROW - SUNDAY JULY 05
Fairly sunny - scorching heat getting sultry - evening thunderstorm risk
SKY CONDITION : clear or partly cloudy - locally cloudy towards the latter part of the afternoo due to cumulus cloud growth over the massifs. period of sunshine close to 80%.
PRECIPITATION : isolated thunderstorm risk in the evening.
WIND - ground level : variable light in the morning ‑ moderate afternoon thermal breeze.
WIND - mid mountain : variable light -> WSW light to moderate.
WIND - high mountain : W -> WSW moderate.
TEMPERATURE : low +18°C - high +36°C.
ISOTHERM 0°C : 4600 -> 4300 m.
ISOTHERM -10°C : 5800 m.
Thunderstorm cell random development to be watched for if high up.
SUNDAY TO MONDAY NIGHT - JULY 05 TO 06
Thunderstorm likely at first - skies clearing partly thereafter
SKY CONDITION  : cloudy or locally mostly cloudy in the evening - becoming partly cloudy towards the latter part of the night - persistent high cloud as well.
PRECIPITATION : isolated thunderstorm risk unti the middle of the night.
WIND - aloft : WSW moderate -> moderate to strong -> W moderate.
TEMPERATURE : low +17°C.
Uncertain.
MONDAY JULY 06
Fairly sunny - some high cloud ‑ very dry - scorching heat
SKY CONDITION : clear or partly cloudy - high cloud - cumulus cloud growth in the afternoon. Period of sunshine close to 80%.
PRECIPITATION : none.
WIND - aloft : W moderate -> WSW light to moderate.
TEMPERATURE : low +16 °C - high +34°C.
Thunderstorm risk seems very low all over the area. Uncertain.
TUESDAY JULY 07
Fairly sunny ‑ sultry scorching heat ‑ evening thundery deterioration likely
SKY CONDITION : clear or partly cloudy in the morning - becoming cloudy - locally mostly cloudy towards the end of the afternoon. Period of sunshine close to 70%.
PRECIPITATION : thunderstorm likely towards the evening.
WIND - aloft : WSW light to moderate -> moderate to strong.
TEMPERATURE : low +15°C - high +36°C.
Uncertain.
EXTENDED OUTLOOK UNTIL FRIDAY JULY 10 2015

Wednesday : changeable - bright sunny spells and cloud patches in turn - shower risk - cooler than the previous day ‑ decreasing westerly wind high up. Thursday and Friday : fair sunny weather ‑ getting hotter in the afternoon as time goes by.

Forecast reliability : fairly good until Sunday ‑ poor thereafter.

ReportsAs a reminder, today in Chamonix, the sun rises at 05:48:36 and goes down at 21:25:40.
45.55 N 6.51 E - Altitude 1040 m
5 July 07:00
Temperature +15°C
Relative humidity 80%
Wind 0 km/h
Sea level pressure 1026 hpa - falling slowly
Pressure at 1042 m 904 mb
Precipitation last 6h 0.0 mm
Skies clear - slightly hazy
Visibility 60000 m
Altitude 3845 m
5 July 07:00
Temperature +2°C
Wind WSW 30 km/h
Altitude 2250 m
5 July 06:00
Snow depth 0 cm
Wind 15 km/h
Gusts 20 km/h
Temperature +16°C