CHAMONIX VALLEY AND MONT-BLANC AREA WEATHER FORECAST

From http://chamonix-meteo.com

ISSUED AT 08:15 SUNDAY DECEMBER 15

GENERAL SYNOPSIS

While refocusing over British Isles, North‑Atlantic huge low pressure system makes altitude stream back southwest over France and the Alps. Simultaneous pressure rise over Central Mediterranean and Northern Italy will shape fœhn gradient between Savoie and Italian Piedmont, +8 hpa as soon as tonight, which will tighten further until reaching +14 hpa during the night to Tuesday. This is a figure likely to causing some violent phenomenon. • Milder trend will continue or go intensifying on Sunday, with strong winds still blowing high up and with fairly large sunny spells, mostly in the afternoon. • Foehn will help temperature highs rising further, noticeably above +10°C in the valley on Monday and Tuesday.

TODAY - SUNDAY DECEMBER 15

Getting milder with fair sunny spells in the afternoon ‑ strong wind high up

SKY CONDITION : frequent cloud crossing above 3000 m this morning in the southern fringes of unsettled circulation ‑ becoming partly cloudy in the afternoon. Period of sunshine close to 60%.
PRECIPITATION : none.
WIND - ground level : calm ‑> SW ‑> variable light.
TEMPERATURE : low 0°C - high +8°C.
ISOTHERM 0°C : 2300 ‑> 2600 m.
ROAD CONDITION  : Montets Pass is open. (Sunday. 16:00).

OVERNIGHT

High cloud patches becoming fairly thick ‑ foehn getting up

SKY CONDITION : fairly thin high cloud crossing over at first, then shaping thicker patches.
PRECIPITATION : none.
WIND - aloft : WSW ‑> SW strong ‑ fœhn getting up in the valley, moderate.
TEMPERATURE : low ‑1°C.

MONDAY DECEMBER 16

Fairly sunny and very mild with foehn increasing to near gale ‑ strong wind high up

SKY CONDITION : fairly thick high cloud patches and fair sunny spells in turn. Period of sunshine close to 65%.
PRECIPITATION : none.
WIND - aloft : SW ‑> SSW strong ‑ strong foehn in the valley, increasing further at night.
TEMPERATURE : low +3 °C - high +9°C.

TUESDAY DECEMBER 17

Very strong foehn at first ‑ sunny outbreaks among cloud running over from south

SKY CONDITION : fœhn generated sunny spells in the morning ‑ then becoming mostly cloudy during the afternoon. Period of sunshine close to 50%.
PRECIPITATION : some shower may run over the northern slopes of the Massif.
WIND - aloft : S strong ‑> moderate to strong ‑ near gale foehn in the valley at first, decreasing later.
TEMPERATURE : rising highs.

EXTENDED OUTLOOK UNTIL FRIDAY DECEMBER 20 2019