CHAMONIX VALLEY AND MONT-BLANC AREA WEATHER FORECAST
ISSUED AT 09:00 MONDAY JUNE 27 2022
VALID : MONDAY JUNE 27 -- SATURDAY JULY 02 2022
Brief night —
Dew drop caught in
The caterpillar's fur
UNSETTLED AT TIMES • Low 998 hpa, NW close to Scotland, moving slowly away towards Iceland, extending a frontal trough up to the Pyrénées. Linked cold front is currently waving along N slopes of the Alpine Range, getting slowly closer. It bumps currently into past week-end's fair condition, while it's unsettled part is expected to moving away NE in the evening. • Moreover, this Scottish low is currently driving a powerful SW high up, Gibraltar to Scandinavia. • Instability will remain as a determining cause on Tuesday, until next high pressure altitude push from the Mediterranean will allow for a fair, stable and hot condition by Wednesday. • Further outlook is uncertain.
TODAY - MONDAY JUNE 27
SKY CONDITION : fair sunny outbreaks this morning, above broken cloud layer in the median altitude range - then skies becoming fairly soon ominous, mostly cloudy to overcast from SW towards noon. Period of sunshine close to 30%.
PRECIPITATION : starting up towards noon - scattered shower, yet locally fairly heavy and with possible thunderclap - moving away NE by nightfall - rain-snow limit towards 3700 m, somewhat lower at times - expected water amount in the valley : 6-8 mm.
WIND - ground level : variable very light -> SW light.
WIND - mid mountain : SSW light to moderate -> SW moderate - locally moderate to strong.
WIND - high mountain : SW gale force - occasionally moderate to strong.
TEMPERATURE : low +13°C - high +22°C.
ISOTHERM 0°C : 4000 -> 4100 -> 4000 m.
ISOTHERM -10°C : 5500 -> 5600 -> 5500 m.
SKY CONDITION : chaotic mainly cloudy by nightfall - becoming cloudy over the hours, and locally partly cloudy towards the latter part - high up, possible yet random radiation and snow-surface re-freezing as well - iso 0°C towards 4000 m.
PRECIPITATION : isolated shower still possible until the middle of the night - rain-snow limit dropping towards 3500 m.
WIND - aloft : SW gale force - occasionally severe gale -> moderate to strong.
TEMPERATURE : low +13°C.
TUESDAY JUNE 28
SKY CONDITION : some sunny spell among very changeable skies with cloud patches early in the morning - becoming quickly mostly cloudy to overcast. Period of sunshine close to 25%.
PRECIPITATION : shower resuming shortly before noon - maybe locally heavy with thunderstorm towards the latter part of the afternoon - rain-snow limit dropping towards 3400 m at times - possible water amount in the valley : 10-15 mm.
WIND - aloft : SW moderate to strong -> NW light to moderate.
TEMPERATURE : low +12 °C - high +21°C.
WEDNESDAY JUNE 29
SKY CONDITION : fairly sunny after dispelling of late night's cloud remains - fair weather cumulus cloud above the massifs in the afternoon. Period of sunshine close to 70%.
PRECIPITATION : none.
WIND - aloft : WNW -> WSW - moderate or occasionally light to moderate.
TEMPERATURE : rising lows - slightly dropping highs.
EXTENDED OUTLOOK UNTIL SATURDAY JULY 02 2022
Thursday : fairly sunny - noticeable convection expected in the afternoon, making cumulus cloud grow bulky above the massifs, then scattered shower towards evening - SW high up, moderate or occasionally moderate to strong. Friday : uncertain - SW resumes streaming unsettled upon cold front crossing over from NW, occasionally fairly active (10 mm). Saturday : uncertain - fair weather likely, cool in the morning, then hot (28-29°C) in the afternoon.
Forecast reliability : fairly good until Tuesday - poor thereafter.