CHAMONIX VALLEY AND MONT-BLANC AREA WEATHER FORECAST
ISSUED AT 20:45 ON SUNDAY JULY 15, 2018
VALID FROM : SUNDAY JULY 15 -- UNTIL : SATURDAY JULY 21 2018
The carp's head
Loose gradient area over the Mediterranean Basin, France, Italy and a large western part of the Alpine Range. • Altitude cold low, Northwestern Iberian Peninsula, driving unstable and humid puffs embedded in a mainly westerly stream, Northern Spain to Central Europe, thus allowing for random thunderstorm cell development. • Fairly heavy thunderstorm crossing over our Region this evening. Lull spreading towards the latter part of the night. • After a fairly sunny morning, several thundery shower or thunderstorm passings will occur until Monday evening the most active upon nortwesterly veering of the altitude stream. • Instability will probably be locally declining, Tuesday to Thursday, before spreading again during the week-end.
SUNDAY EVENING JULY 15 - AND OVERNIGHT
SKY CONDITION : mostly cloudy - becoming partly cloudy to cloudy towards the latter part of the night - high cloud crossing over.
PRECIPITATION : scattered thundery showers or thunderstorms in the first part of the night - rain-snow limit towards 3500 m.
WIND - ground level : SW light -> calm - thunderstorm gust still possible early in the night.
WIND - mid mountain : WSW light to moderate -> W light.
WIND - high mountain : W moderate to strong -> WSW moderate.
TEMPERATURE : low +11°C.
ISOTHERM 0°C : 3900 -> 3800 m.
ISOTHERM -10°C : 5200 -> 5300 m.
TOMORROW - MONDAY JULY 16
SKY CONDITION : cloudy with sunny spells in the morning - becoming mostly cloudy. Period of sunshine close to 50%.
PRECIPITATION : thundery shower or thunderstorm passing in the afternoon - rain-snow limit towards 3500 m.
WIND - ground level : calm -> variable light.
WIND - mid mountain : W -> SW -> NW light.
WIND - high mountain : WSW moderate -> NW light to moderate.
TEMPERATURE : low +11°C - high +24°C.
ISOTHERM 0°C : 3800 m.
ISOTHERM -10°C : 5300 m.
MONDAY TO TUESDAY NIGHT - JULY 16 TO 17
SKY CONDITION : mostly cloudy - becoming cloudy towards the latter part of the night, then partly cloudy by dawn.
PRECIPITATION : scattered thundery showers in the first part of the night - rain-snow limit towards 3500 m.
WIND - aloft : NW light to moderate -> light.
TEMPERATURE : low +10°C.
TUESDAY JULY 17
SKY CONDITION : fair sunny spells, especially in the morning - cloud passings probably more frequent in the afternoon. Period of sunshine close to 60%.
PRECIPITATION : afternoon thundery shower risk - rain-snow limit towards 3400 m.
WIND - aloft : WNW light -> moderate.
TEMPERATURE : low +9 °C - high +24°C.
WEDNESDAY JULY 18
SKY CONDITION : clear or partly cloudy. Period of sunshine close to 90%.
PRECIPITATION : none.
WIND - aloft : W light to moderate.
TEMPERATURE : low +8°C - high +28°C.
EXTENDED OUTLOOK UNTIL SAT. JULY 21
Thursday : sunny morning ‑ locally cloudy with shower risk in the afternoon. Friday : uncertain ‑ sunny outbreaks in the morning ‑ becoming cloudy with moderate shower later. Saturday : very uncertain - partly sunny - afternoon shower likely.
Forecast reliability : poor.