CHAMONIX VALLEY AND MONT-BLANC AREA WEATHER FORECAST


Matsuo Bashō
Snowy morning
All alone I chew
Dried Salmon
ISSUED AT 08:20 TUESDAY JANUARY 21
VALID FROM : TUESDAY JANUARY 21 ‑‑ UNTIL : SUNDAY JANUARY 26 2020

GENERAL SYNOPSIS
Powerful high, Ireland (1043) to Northwestern Balkans (1045) is bending over 1010 low whirling in the Alboran Sea, east of Gibraltar. The latter is linked to an altitude cold cut‑off which lies west close to the Strait. • Fairly light southeast stream resulting high up, with air mass conflict mainly confined south of the Alpine Barrier, even if some high cloud veil may be running over northward. This Tuesday is therefore expected pretty sunny on the whole, in a still milder atmosphere, thanks to last night’s foehn puffs in valley. • Milder trend will continue on Wednesday and Thursday, especially in the median altitude range, under amazingly fair sunshine. • Deterioration by Friday, still fairly uncertain for now.
TODAY - TUESDAY JANUARY 21
Sunny ‑ rising temperatures ‑ some high cloud veils crossing in the afternoon
SKY CONDITION : clear or partly cloudy ‑ thin high cloud running over from south or southeast. Period of sunshine close to 85%.
PRECIPITATION : none.
WIND - ground level : NE light to moderate ‑ occasionally moderate foehny in the morning.
WIND - mid mountain : SE ‑> SSE light to moderate.
WIND - high mountain : ESE ‑> SSE light to moderate.
TEMPERATURE : low ‑3°C - high +6°C.
ISOTHERM 0°C : 2100 ‑> 2500 m.
ISOTHERM -10°C : 3700 ‑> 3900 m.
OVERNIGHT
Mainly clear ‑ cold in the valley ‑ milder in the median altitude range
SKY CONDITION : clear or partly cloudy ‑ high cloud still likely ti running over from south early in the night.
PRECIPITATION : none.
WIND - aloft : SSE light to moderate.
TEMPERATURE : low ‑4°C - temperature inversion toward 1500 m.
WEDNESDAY JANUARY 22
Fair weather ‑ getting further mild, especially in the median altitude range
SKY CONDITION : clear. Period of sunshine close to 100%.
PRECIPITATION : none.
WIND - aloft : SSE ‑> S light to moderate.
TEMPERATURE : low ‑5 °C - high +8°C - temperature inversion toward 1300 m early in the morning.
THURSDAY JANUARY 23
Amazingly fair weather ‑ very mild in the median altitude range later
SKY CONDITION : clear or partly cloudy. Period of sunshine close to 90%.
PRECIPITATION : none.
WIND - aloft : SSE moderate ‑> S moderate to strong.
TEMPERATURE : rising.
EXTENDED OUTLOOK UNTIL SUNDAY JANUARY 26 2020

Friday : cloudy to mostly cloudy ‑ short foehn spell towards the middle of the day, then slight shower risk, possible snow flurries ‑ fairly strong south in the massif, decreasing. Saturday : light westerly stream high up ‑ some sunny spells ‑ rather mild in the afternoon ‑ dry. Sunday : uncertain ‑ possibly fairly sunny ‑ milder than seasonal average.

Forecast reliability : fairly good until Thursday ‑ poor thereafter.

ReportsAs a reminder, today in Chamonix, the sun rises at 08:05:47 and goes down at 17:21:48.
45.55 N 6.51 E - Altitude 1020 m
January 21 07:00
Temperature -2°C
Relative humidity 66%
Wind NE 5 km/h
Sea level pressure 1035 hpa - rising slowly
Pressure at 1042 m 916 mb
Precipitation last 6h 0.0 mm
Skies clear - cold foehn puffs - snow depth : 18 cm
Visibility 95000 m
Altitude 3845 m
January 21 07:00
Temperature -10°C
Wind S 25 km/h
Altitude 2250 m
January 21 06:00
Snow depth 102 cm
Wind 0 km/h
Gusts -- km/h
Temperature -1°C