CHAMONIX VALLEY AND MONT-BLANC AREA WEATHER FORECAST


Natsume Sôseki
The chalet
Silently unveils
The secret of snow
ISSUED AT 08:00 THURSDAY JANUARY 18
VALID FROM : THURSDAY JANUARY 18 ‑‑ UNTIL : TUESDAY JANUARY 23 2018

GENERAL SYNOPSIS
Powerful low system, southeast of Greenland to Baltic Sea. It is filling on the spot, yet shaping a fairly tight gradient with the Azores high, thus making strong to gale force winds blow over the Alpine Range, between west and northwest. • Series of frontal disturbances embedded in that flow makes the rain‑snow limit rise and drop in turn. • Today, it is an active warm front which will pass throughout our Regions; it is linked to a satellite minimum, currently 977 hpa North Sea, moving swiftly towards Southern Denmark. Rain‑snow limit is therefore expected to rising up towards 1500 m in the evening. • Cold front is expected to crossing over towards the latter part of the night. • High and fast changeability of the implied phenomena, requires to monitor their development carefully.
TODAY - THURSDAY JANUARY 18
Snow showers, light, then moderate, turning into rain ‑ strong wind high up
SKY CONDITION : mostly cloudy to overcast. Period of sunshine close to 0%.
PRECIPITATION : light and scattered snow showers at first, turning into moderate rain in the afternoon ‑ rain‑snow limit towards 600 m at first, rising up towards 1500 m in the evening ‑ expected snowfall towards 1800 m : 25‑35 cm, windblown.
WIND - ground level : SW light.
WIND - mid mountain : WSW moderate ‑ moderate to strong at times.
WIND - high mountain : WNW strong.
TEMPERATURE : low ‑2°C - high +2°C.
ISOTHERM 0°C : 900 ‑> 1800 m.
ISOTHERM -10°C : 3200 ‑> 3600 m.
ROAD CONDITION  : snow covered roadways above 700 m besides treated itineraries.
Route des Gaillands closed. Montets and Forclaz Passes closed. (Thu. 06:30).
morelive precipitation radar over the Alps
OVERNIGHT
Moderate rain, turning into light snow snower ‑ strong wind high up
SKY CONDITION : mostly cloudy to overcast.
PRECIPITATION : moderate at first ‑ getting lighter by dawn ‑ rain‑snow limit dropping towards 1000 m by the end of the night ‑ expected snowfall towards 1800 m : 10‑15 cm, windblown.
WIND - aloft : WNW ‑> W strong.
TEMPERATURE : low 0°C.
FRIDAY JANUARY 19
Unsettled ‑ relative precipitation lull ‑ strong wind high up
SKY CONDITION : mostly cloudy on the whole ‑ at times cloudy with fleeting sunny spells in the afternoon. Period of sunshine close to 25%.
PRECIPITATION : light and scattered on the whole ‑ somewhat heavier snow showers in the afternoon ‑ rain‑snow limit, probably dropping towards 600 m ‑ expected snowfall towards 1800 m : 10‑15 cm, windblown.
WIND - aloft : W ‑> WNW strong.
TEMPERATURE : low ‑3 °C - high 0°C.
SATURDAY JANUARY 20
Low pressure ‑ moderate to heavy snowfall in the afternoon ‑ gale high up
SKY CONDITION : mostly cloudy to overcast. Period of sunshine close to 0%.
PRECIPITATION : light and scattered shower in the morning ‑ turning into moderate and continuous precipitation ‑ rain‑snow limit towards 700 m, rising up towards 1000 m in the evening ‑ expected snowfall towards 1800 m : 25‑40 cm, windblown.
WIND - aloft : NW strong ‑> gale force.
TEMPERATURE : steady or dropping slightly.
EXTENDED OUTLOOK UNTIL TUESDAY JANUARY 23 2018

Sunday : getting steeply milder ‑ light snow in the morning ‑ heavy rain likely in the afternoon ‑ NNW gale high up. Monday : gloomy ‑ moderate rain ‑ still much wind high up, mainly NW, decreasing slowly. Tuesday : thaw continues ‑ fair sunny spells likely in the afternoon.

Forecast reliability : poor.

ReportsAs a reminder, today in Chamonix, the sun rises at 08:07:45 and goes down at 17:18:21.
45.55 N 6.51 E - Altitude 1040 m
January 18 08:00
Temperature -2°C
Relative humidity 93%
Wind SW 5 km/h
Sea level pressure 1018 hpa - rising slowly
Pressure at 1042 m 900 mb
Precipitation last 6h 0.0 mm
Skies overcast - snow flurries
snow depth : 46 cm
Visibility 2000 m
Altitude 3845 m
January 18 07:00
Temperature -16°C
Wind WNW 120 km/h
Altitude 2250 m
January 18 06:00
Snow depth 275 cm
Wind 45 km/h
Gusts 55 km/h
Temperature -8°C