CHAMONIX VALLEY AND MONT-BLANC AREA WEATHER FORECAST


Matsuo Bashō
While dawn appears
Swirling in fog eddies
The bell clears its voice
ISSUED AT 20:00 ON SATURDAY FEBRUARY 24, 2018
VALID FROM : SATURDAY FEBRUARY 24 2018 -- UNTIL : FRIDAY MARCH 02 2018

GENERAL SYNOPSIS
Extended High, 1049-1024 hpa Barents Sea to Northern France, strengthening 1050-1030 hpa by Sunday noon. Altitude thalweg development by the same time, will channelize a continental polar air inflow, Northwestern Siberian to the Alps. Low 1002 hpa currently lying east of the Bonifacio Strait will be deepening slightly, shaping a northeasterly stream high up, which will be backing north and starting up to getting colder overnight. • Cooling will continue on Sunday under clear skies high up with an uncertain stratus cloud infiltration from the northeast toping towards 1800 m. • Fairly sunny weather, yet bitter cold, Monday to Wednesday. • Unsettled westerly to southwesterly pattern expected to resuming as of Wednesday evening, with fœhn spells and weak disturbed passings in turn, in a well enough cold atmophere to cause some snowfall at the lower levels, at least until the week-end.
SATURDAY EVENING FEBRUARY 24 - AND OVERNIGHT
Partly cloudy and slightly misty in a cooling atmosphere
SKY CONDITION : partly cloudy - high cloud crossing over from the north - broken stratus cloud toping towards 1800 m likely to infiltrating from the northeast.
PRECIPITATION : none.
WIND - ground level : calm or SW very light.
WIND - mid mountain : calm or SW very light.
WIND - high mountain : NNE light -> N light to moderate.
TEMPERATURE : low -5°C.
ISOTHERM 0°C : 2200 -> 1600 m.
ISOTHERM -10°C : 3700 -> 3200 m.
Temperature inversion towards 1700 m.
ROAD CONDITION  : dry roadways on the whole. Some icy snow patches persisting besides salted itineraries.
Forclaz Pass is closed. (Sat. 18:00).
morelive precipitation radar over the Alps
TOMORROW - SUNDAY FEBRUARY 25
Fairly sunny ‑ getting noticeably colder, especially in the median altitude range
SKY CONDITION : possible broken stratus cloud early in the morning, toping towards 1800 m - else clear or partly cloudy - some high cloud passings. Period of sunshine close to 65%.
PRECIPITATION : none.
WIND - ground level : SW very light -> calm -> NE light.
WIND - mid mountain : calm -> variable light -> NE light to moderate.
WIND - high mountain : N light to moderate -> NNW -> N moderate.
TEMPERATURE : low -7°C - high 0°C.
ISOTHERM 0°C : 1600 -> 600 m.
ISOTHERM -10°C : 3200 -> 2200 m.
Biting cold early in the afternoon in the median altitude range.
SUNDAY TO MONDAY NIGHT - FEBRUARY 25 TO 26
Clear and bitter cold on the whoel - windy high up
SKY CONDITION  : clear or partly cloudy.
PRECIPITATION : none.
WIND - aloft : N moderate -> NNW moderate to strong.
TEMPERATURE : low -11°C.
Uncertain.
MONDAY FEBRUARY 26
Fairly sunny ‑ getting even colder, especially in the median altitude range
SKY CONDITION : partly cloudy - cloudy with sunny spells at times in the morning. Period of sunshine close to 75%.
PRECIPITATION : none.
WIND - aloft : NW moderate to strong -> NNE light to moderate.
TEMPERATURE : low -12 °C - high -3°C.
Uncertain.
TUESDAY FEBRUARY 27
Fairly sunny ‑ siberian cold
SKY CONDITION : clear or partly cloudy. Period of sunshine close to 70%.
PRECIPITATION : none.
WIND - aloft : NNW -> NW light to moderate.
TEMPERATURE : low -13°C - high -7°C.
Uncertain.
EXTENDED OUTLOOK UNTIL FRIDAY MARCH 02

Wednesday : fairly sunny ‑ siberian cold ‑ westerly gale likely high up in the afternoon - cold fœhn puffs likely in the valley towards the evening. Thursday : warm front crossing over from the southwest - mainly cloudy with snow showers in the morning - gusty fœhn increasing in the afternoon, thus causing sunny outbreaks in the valley. Friday : gloomy - light snow showers. To be confirmed.

Forecast reliability : Fairly good until Sunday - poor thereafter.

ReportsAs a reminder, today in Chamonix, the sun rises at 07:17:25 and goes down at 18:13:32.
45.55 N 6.51 E - Altitude 1040 m
February 24 07:00
Temperature -4°C
Relative humidity 91%
Wind SW 5 km/h
Sea level pressure 1004 hpa - falling slowly
Pressure at 1042 m 887 mb
Precipitation last 6h 0.0 mm
Skies mostly cloudy - fog patches
snow depth : 58 cm
Visibility 8000 m
Altitude 3845 m
February 24 07:00
Temperature -12°C
Wind SE 50 km/h
Altitude 2250 m
February 24 18:00
Snow depth 350 cm
Wind 20 km/h
Gusts 45 km/h
Temperature 0°C