CHAMONIX VALLEY AND MONT-BLANC AREA WEATHER FORECAST


Tomiyasu Fūsei
There's nothing
He doesn't know—
The cat on the stove
ISSUED AT 19:40 ON THURSDAY APRIL 24, 2014
VALID FROM : THURSDAY APRIL 24 -- UNTIL : WEDNESDAY APRIL 30 2014

GENERAL SYNOPSIS
Deepening minimum 1011 hpa tonight, Pyrénées to Central France, expected to drifting towards Sardinia within Friday evening and driving very unsettled, humid and still fairly mild air towards the Alps, expected to triggering a rainy-thundery deterioration by Friday afternoon. Temporary pressure rise from the southwest over France during the following night, causing sunny improvement on Saturday. Fairly deep low coming in over Southern Ireland, and further over the Western English Channel by Sunday. Linked disturbance slowly crossing over the area, thus possibly causing heavy precipitation during the main part of the day.
THURSDAY EVENING APRIL 24 - AND OVERNIGHT
Cloudy deterioration from the southwest - probably dry
SKY CONDITION : partly cloudy to cloudy, becoming cloudy to mostly cloudy - cumulus cloud vanishing while thickening high cloud.
PRECIPITATION : probably none.
WIND - ground level : variable light.
WIND - mid mountain : variable -> SE light.
WIND - high mountain : SW -> SSW light to moderate.
TEMPERATURE : low +6°C.
ISOTHERM 0°C : 2800 -> 2600 m.
ISOTHERM -10°C : 4000 m.
Uncertain.
TOMORROW - FRIDAY APRIL 25
Unsettled - mainly cloudy in the morning - becoming rainy
SKY CONDITION : cloudy to mostly cloudy early in the morning - possible fleeting sunny spells - becoming quickly overcast. period of sunshine close to 10%.
PRECIPITATION : shower starting up towards the middle of the day, with possible local thunderstorm, then changing to continuous rain, at times moderate towards the latter part of the afternoon - rain-snow limit towards 2300 m, dropping towards 2000 m at night.
WIND - ground level : variable light.
WIND - mid mountain : SE -> S light.
WIND - high mountain : SSW -> SSE light to moderate -> E faible.
TEMPERATURE : low +6°C - high +15°C.
ISOTHERM 0°C : 2600 -> 2400 m.
ISOTHERM -10°C : 4000 -> 3800 m.
Uncertain.
FRIDAY TO SATURDAY NIGHT - APRIL 25 TO 26
Improving
SKY CONDITION  : mostly cloudy - becoming cloudy with clear spells, high up at first - possible persistent low cloud.
PRECIPITATION : decreasing in the first part of the night - dry later.
WIND - aloft : E -> S light.
TEMPERATURE : low +4°C.
Uncertain.
SATURDAY APRIL 26
Fairly sunny in the morning ‑ increasing cloud in the afternoon - shower risk later
SKY CONDITION : early morning low cloud likely, otherwise clear or partly cloudy in the morning - increasing cloud from the west during the afternoon. Period of sunshine close to 55%.
PRECIPITATION : evening shower risk - rain-snow limit towards 2000 m.
WIND - aloft : S light -> WSW moderate.
TEMPERATURE : low +4 °C - high +16°C.
Uncertain.
SUNDAY APRIL 27
Very active disturbance crossing over ‑ heavy precipitation
SKY CONDITION : overcast. Period of sunshine close to 0%.
PRECIPITATION : continuous - moderate to heavy - at times very heavy towards the middle of the day - rain-snow limit towards 1600 m, dropping towards 1300 m.
WIND - aloft : SE moderate - moderate to strong at times.
TEMPERATURE : low +4°C - high +10°C.
Uncertain.
EXTENDED OUTLOOK UNTIL WEDNESDAY APRIL 30 2014

Monday : unsettled and cool ‑ few sunny spells ‑ showers, becoming scattered later. Tuesday : Unsettled ‑ morning sunny spells ‑ showers later. Wednesday : very uncertain - probably fairly sunny - afternoon shower risk however.

Forecast reliability : poor.

ReportsAs a reminder, today in Chamonix, the sun rises at 06:28:19 and goes down at 20:32:32.
45.55 N 6.51 E - Altitude 1040 m
24 April 08:00
Temperature +4°C
Relative humidity 100%
Wind 0 km/h
Sea level pressure 1020 hpa - steady
Pressure at 1042 m 901 mb
Precipitation last 6h 0.0 mm
Skies clear
Visibility 55000 m
Altitude 3845 m
24 April 08:00
Temperature -8°C
Wind -- km/h
Altitude 2250 m
24 April 08:00
Snow depth 60 cm
Wind 5 km/h
Gusts 10 km/h
Temperature 0°C