CHAMONIX VALLEY AND MONT-BLANC AREA WEATHER FORECAST


Taneda Santōka
The sound
Of the raindrops
Grown older as well
ISSUED AT 08:30 THURSDAY MAY 13
VALID FROM : THURSDAY MAY 13 -- UNTIL : TUESDAY MAY 18 2021

GENERAL SYNOPSIS
Low pressure on the whole over Western Europe, with two minima shaping weather of the Alpine Range, Atlantic one towards Central English Channel (1004), and Mediterranean on in the Northern Gulf of Genoa (1006). • Cold front linked to the Channel one is currently crossing over our Region. It is about to disintegrating and will be triggering only light rain until the middle of the day, which will turn thereafter into more and more scattered showers. Rain-snow limit may drop locally towards 1600 m. • Weak high pressure push from Azores overnight and on Friday will probably cause fairly sunny improvement by Friday morning, while high instability will make mostly cloudy afternoon. • Occasionally rainy deterioration as of Saturday afternoon, upon income of fairly deep low west of Ireland.
TODAY - THURSDAY MAY 13
Showery morning - sunny spells back from west in the afternoon - unseasonably cool
SKY CONDITION : mostly cloudy by dawn, then fair morning sunny oubreaks - convection make cumulus cloud grow over the afternoon hours. Period of sunshine close to 35%.
PRECIPITATION : showery from west in the morning - rain-snow limit towards 1600 m - expected snowfall towards 1800 m : ≤ 5 cm.
WIND - ground level : SW very light.
WIND - mid mountain : WSW light.
WIND - high mountain : WSW light to moderate - occasionally NW.
TEMPERATURE : low +5°C - high +13°C.
ISOTHERM 0°C : 1700 -> 2100 m.
ISOTHERM -10°C : 3500 m.
OVERNIGHT
Becoming partly cloudy - not much wind - may be locally sligthly frosty by dawn
SKY CONDITION : cloudy with clear spells, becoming partly cloudy - iso 0°C dropping towards 1900 m.
PRECIPITATION : none.
WIND - aloft : mainly W - light to moderate -> light.
TEMPERATURE : low +2°C.
FRIDAY MAY 14
fair sunny and cold spell early in the morning, then unstable deterioration from west
SKY CONDITION : partly cloudy early in the morning - becoming cloudy with sunny spells by noon, then locally mostly cloudy in the afternoon due to cumulus cloud growth. Period of sunshine close to 40%.
PRECIPITATION : moderate showery spell early in the afternoon - possible remaining light rain along the slopes thereafter - rain-snow limit towards 1600 m - expected snowfall towards 1800 m : ± 5 cm.
WIND - aloft : mainly W - light or occasionally light to moderate.
TEMPERATURE : low +1 °C - high +12°C.
SATURDAY MAY 15
Fleeting sunny spells in the morning, then gloomy with intermittent precipitation
SKY CONDITION : cloudy with fleeting sunny spells in the morning - becoming overcast in the afternoon. Period of sunshine close to 15%.
PRECIPITATION : light and scattered shower early in the afternoon - turning into light rain - rain-snow limit towards 1700 m - expected snowfall towards 1800 m : ± 5 cm.
WIND - aloft : WNW moderate to strong -> W strong.
TEMPERATURE : dropping slightly.
EXTENDED OUTLOOK UNTIL TUESDAY MAY 18 2021

Sunday : slightly low pressure field in the SE fringes of the Irish minimum - after changeable spell between sunny spells and scattered light rain of the warm sector, more considerable rainy deterioration upon approach of the cold front in the afternoon - mainly W, strong high up. Monday : uncertain - the Alpine Range is expected to becoming an evident boundary layer between Atlantic low area northward and Mediterranean high area southward - unstable tail following previous night's disturbance shall trigger shower along northern slope while Italian one will remain sunny - mainly WNW, occasionally fairly strong high up. Tuesday : very uncertain - yet in a trend towards improving in a westerly to northwesterly stream, fairly strong high up, which drives humid waves likely to triggering some showers.

Forecast reliability : fairly good until Friday.

ReportsAs a reminder, today in Chamonix, the sun rises at 06:01:58 and goes down at 20:55:45.
Chamonix - ville
45.55 N 6.51 E - Altitude 1020 m
May 13 08:00
Temperature +6.0°C
Relative humidity 89%
Wind 0 km/h
Sea level pressure 1008 hpa - steady
Pressure at 1042 m 892 mb
Precipitation last 6h 0.0 mm
Skies fair sunny outbreak
Visibility 50000 m
Altitude 3845 m
May 13 07:00
Temperature -11°C
Wind NW 15 km/h
Altitude 2250 m
May 13 07:00
Snow depth 194 cm
Wind W 5 km/h
Gusts 13 km/h
Temperature -1.9°C