CHAMONIX VALLEY AND MONT-BLANC AREA WEATHER FORECAST


Matsuo Bashō
Moon and snow
Seem to be ignoring each other
Happy new year
ISSUED AT 09:20 TUESDAY JANUARY 26
VALID FROM : TUESDAY JANUARY 26 ‑‑ UNTIL : SUNDAY JANUARY 31 2021

GENERAL SYNOPSIS
High pressure bubble has been cut off the Azores High Ridge on the rear side of a very cold polar air inflow high up, Norwegian Sea ‑> Tyrrhenian Sea. Currently lying Massif Central, that bubble is expected to moving up to Austrian Alps over the hours until this evening. Fairly tight gradient of the resulting transition border shapes a powerful north by northwest altitude stream, mostly under fair sunshine, though in a much colder atmosphere than seasonable. • Westerly procession of frontal disturbances is expected to resuming by Wednesday upon income of a probably weak warm front towards the middle of the day. • Bad westerlies and further mild atmosphere will persist on Thursday and Friday, requiring careful monitoring day after day.
TODAY - TUESDAY JANUARY 26
Fairly sunny and very cold in the morning ‑ becoming cloudy later, with whole gale high up
SKY CONDITION : clear overall and with outstanding visibility above 2300 m this early morning ‑ recently condensed stratus cloud expected to dispelling fairly soon under direct sunshine ‑ becoming cloudy in the afternoon, with widespread high cloud getting rather thick in the evening. Period of sunshine close to 75%.
PRECIPITATION : none.
WIND - ground level : variable light ‑ light yet very cold Bise puffs from the upper part of the valley.
WIND - mid mountain : mainly NW ‑ light or occasionally light to moderate.
WIND - high mountain : NW near gale.
TEMPERATURE : low ‑9°C - high 0°C.
ISOTHERM 0°C : 500 ‑> 900 m.
ISOTHERM -10°C : 2000 ‑> 1400 m.
ROAD CONDITION  : dry and very cold - roadways mainly free of snow (Tuesday, 05:45).morelive precipitation radar over the Alps
OVERNIGHT
Covered skies without precipitation ‑ very cold in the valley ‑ very strong wind high up
SKY CONDITION : mostly cloudy, then overcast, rather thick cloud cover ‑ ceiling towards 2300 m by the end ‑ iso 0°C rising up towards 1200 m.
PRECIPITATION : probably none until dawn.
WIND - aloft : NW near gale.
TEMPERATURE : low ‑7°C.
WEDNESDAY JANUARY 27
Scattered light snow shower ‑ lots of wind high up, still ‑ somewhat milder later
SKY CONDITION : mostly cloudy ‑ ceiling often towards 1800 m, probably. Period of sunshine close to 0%.
PRECIPITATION : light and scattered shower in the morning ‑ becoming continuous in the afternoon and occasionally moderate ‑ rain‑snow limit towards 600‑700 m ‑ expected snowfall towards 1200 m : 20‑25 cm.
WIND - aloft : NW near gale.
TEMPERATURE : low ‑7 °C - high +1°C.
THURSDAY JANUARY 28
Bad westerly weather, noticeably milder ‑ quite heavy snowfall and lots of wind high up
SKY CONDITION : overcast ‑ ceiling towards 1600 m. Period of sunshine close to 0%.
PRECIPITATION : continuous and locally fairly heavy ‑ rain‑snow limit rising up towards 1600 m ‑ expected snowfall towards 1800 m : 50‑70 cm, windblown.
WIND - aloft : NW near gale.
TEMPERATURE : dropping lows ‑ rising highs.
EXTENDED OUTLOOK UNTIL SUNDAY JANUARY 31 2021

Friday : unseasonably mild ‑ fairly heavy precipitation ‑ snow towards 1400‑1500 m ‑ west by northwest severe gale high up. Saturday : very unsettled, fairly heavy wintry precipitation ‑ rain‑snow limit dropping towards 1200 m ‑ west by northwest fairly strong high up, decreasing. Sunday : relative lull in a much colder tail, barely active ‑ some light snow reaching lowest altitude in the morning ‑ sunny spells later.

Forecast reliability : fairly good until Thursday.

ReportsAs a reminder, today in Chamonix, the sun rises at 08:00:24 and goes down at 17:29:58.
Chamonix - ville
45.55 N 6.51 E - Altitude 1020 m
January 26 - 08:00
Temperature -8.5°C
Relative humidity 89%
Wind 0 km/h
Sea level pressure 1018 hpa - rising
Pressure at 1042 m 900 mb
Precipitation last 6h 0.0 mm
Skies cloudy - stratus cloud patches - 73 cm snow layer
Visibility 10000 m
Altitude 3845 m
January 26 - 07:00
Temperature -22°C
Wind NNW 50 km/h
Altitude 2250 m
January 26 - 07:00
Snow depth 92 cm
Wind W 7 km/h
Gusts 14 km/h
Temperature -16°C