CHAMONIX VALLEY AND MONT-BLANC AREA WEATHER FORECAST


Masaoka Shiki
Summer rain
Drums at
The carp's head
ISSUED AT 19:30 ON SUNDAY JULY 24, 2016
VALID FROM : SUNDAY JULY 24 -- UNTIL : SATURDAY JULY 30 2016

GENERAL SYNOPSIS
Extended low whirling between Iceland and Ireland, fairly shallow, yet expected to refocusing while deepening slightly north close to Scotland by Monday evening. The area of instablility currently matching the loose pressure gradient which is sprawling between the Genoa Gulf and Southern Germany will be repelled eastward by the increasing influence of the Azores high ridge towards the Alp. • This evening's showers will be ending soon, allowing for a clear night sky. • Context remaining slack on the whole, diurnal evolution might lead again to some isolated thundery shower over the massifs towards on Monday late afternoon. • Instability will be decreasing further on Tuesday; however light cool air income from the northwest high up might reactivate it on Wednesday. Further outlook seems fairly uncertain.
SUNDAY EVENING JULY 24 - AND OVERNIGHT
Nighttime alleviates instability - clearing skies
SKY CONDITION : cloudy to mostly cloudy at first - becoming cloudy with clear spells, then partly cloudy.
PRECIPITATION : none.
WIND - ground level : SW -> variable -> NE light.
WIND - mid mountain : variable -> NE light.
WIND - high mountain : NE -> N light.
TEMPERATURE : low +11°C.
ISOTHERM 0°C : 4100 m.
ISOTHERM -10°C : 5700 -> 5800 m.
Possible broken cloud patches down in the valley towards the latter part of the night.
TOMORROW - MONDAY JULY 25
Sultry - sunny morning - fat cumulus cloud growth with isolated shower risk later
SKY CONDITION : sunny morning - becoming cloudy or locally mostly cloudy in the afternoon - large cumulus cloud growth over the massifs. Period of sunshine close to 60%.
PRECIPITATION : isolated thundery shower risk towards the latter part of the afternoon - rain-snow limit towards 3900 m.
WIND - ground level : NE -> thermal SW -> variable light.
WIND - mid mountain : NE -> variable -> NW light.
WIND - high mountain : N -> W light.
TEMPERATURE : low +11°C - high +24°C.
ISOTHERM 0°C : 4100 -> 4200 m.
ISOTHERM -10°C : 5800 m.
Uncertain.
MONDAY TO TUESDAY NIGHT - JULY 25 TO 26
Clearing skies - cool by dawn
SKY CONDITION  : cloudy at first - becoming clear or partly cloudy.
PRECIPITATION : none.
WIND - aloft : W light -> light to moderate.
TEMPERATURE : low +9°C.
Uncertain.
TUESDAY JULY 26
Fairly sunny - somewhat cool in the morning - warm in the afternoon
SKY CONDITION : clear or partly cloudy in the morning - becoming cloudy during the afternoon. Period of sunshine close to 75%.
PRECIPITATION : none.
WIND - aloft : W light to moderate -> light.
TEMPERATURE : low +11 °C - high +25°C.
Uncertain.
WEDNESDAY JULY 27
Sunny morning - cloudy deterioration in the afternoon - getting colder high up
SKY CONDITION : clear or partly cloudy in the morning - becoming cloudy or locally mostly cloudy in the afternoon. Period of sunshine close to 50%.
PRECIPITATION : late afternoon shower slight risk.
WIND - aloft : WSW -> W faible à modéré.
TEMPERATURE : low +11°C - high +22°C.
Very uncertain.
EXTENDED OUTLOOK UNTIL SATURDAY JULY 30

Thursday and Friday : sunny ‑ cool in the morning ‑ getting hot over the days in the afternoon. Saturday : falling pressure, loose gradient over the Alps, thus resuming instability causing rainy-thundery deterioration later. From Thursday evening, altitude stream, mainly W, might increase to fairly strong.

Forecast reliability : poor.

ReportsAs a reminder, today in Chamonix, the sun rises at 06:08:10 and goes down at 21:09:57.
45.55 N 6.51 E - Altitude 1040 m
25 July 07:00
Temperature +10°C
Relative humidity 90%
Wind 0 km/h
Sea level pressure 1022 hpa - falling slowly
Pressure at 1042 m 905 mb
Precipitation last 6h 0.0 mm
Skies clear
Visibility 75000 m
Altitude 3845 m
25 July 07:00
Temperature -1°C
Wind N 10 km/h
Altitude 2250 m
25 July 06:00
Snow depth 0 cm
Wind 10 km/h
Gusts 20 km/h
Temperature +10°C