CHAMONIX VALLEY AND MONT-BLANC AREA WEATHER FORECAST


Yosa Buson
Brief night —
Dew drop caught in
The caterpillar's fur
ISSUED AT 08:30 SUNDAY MAY 31
VALID FROM : SUNDAY MAY 31 ‑‑ UNTIL : FRIDAY JUNE 5 2020

GENERAL SYNOPSIS
High 1035, Southwest Scandinavia, and 1017‑1019 over the Alps, going along with altitude high ridge, Spain to English Channel. • Until Wednesday, all that high pressure area will get gradually weaker, allowing for an isobaric swamp to spread out over a large part of Europe. Its pressure field will become decisively low as an altitude polar air thalweg will intrude over British Isles; some successive cut‑offs at its southern tip will then affect Northern France and shape very unstable weather over the Alpine Range during a large latter part of the week. • This might be quite an uncertain sequence in detail, needing watchful monitoring day after day.
TODAY - SUNDAY MAY 31
Fairly sunny ‑ cool in the morning ‑ rather warm in the afternoon
SKY CONDITION : clear or partly cloudy in the morning ‑ becoming partly cloudy to cloudy with sunny spells while convection keeps making cumulus cloud grow above the massifs during the afternoon. Period of sunshine close to 70%.
PRECIPITATION : none.
WIND - ground level : calm ‑> thermal SW light ‑> calm.
WIND - mid mountain : WSW light ‑> calm ‑> NE light.
WIND - high mountain : N ‑> NW light to moderate.
TEMPERATURE : low +6°C - high +20°C.
ISOTHERM 0°C : 2700 ‑> 3100 m.
ISOTHERM -10°C : 4500 ‑> 4800 m.
OVERNIGHT
Skies clearing quickly ‑ atmosphere getting rather cool in the valley
SKY CONDITION : clear after evening cumulus cloud dispelling, good radiation helps snow surface re‑freezing high up.
PRECIPITATION : none.
WIND - aloft : NW light to moderate ‑> WSW light.
TEMPERATURE : low +6°C.
MONDAY JUNE 1
Fair weather ‑ cool in the morning ‑ quite warm in the afternoon
SKY CONDITION : clear or partly cloudy ‑ cumulus cloud growing above the massifs in the afternoon. Period of sunshine close to 75%.
PRECIPITATION : none.
WIND - aloft : WSW ‑> S or variable light.
TEMPERATURE : low +5 °C - high +24°C.
TUESDAY JUNE 2
Changeable and cooler ‑ fair sunny spells, then mainly cloudy with shower risk
SKY CONDITION : partly cloudy to cloudy with fair sunny spells in the morning. ‑ large cumulus cloud growth in the afternoon. Period of sunshine close to 50%.
PRECIPITATION : thundery shower risk in the afternoon (25%) ‑ rain‑snow limit towards 2800 m.
WIND - aloft : E light ‑> N light to moderate.
TEMPERATURE : slightly rising highs.
EXTENDED OUTLOOK UNTIL FRIDAY JUNE 5 2020

Wednesday : fairly sunny ‑ warm in the afternoon ‑ late afternoon shower likely. Thursday : partly sunny in the morning ‑ mainly cloudy with intermittent rain later ‑ rain‑snow limit towards 3600 m, dropping towards 2800 m in the evening ‑ fairly strong west at times high up. Friday : very uncertain ‑ sunny spells at first, then becoming rainy ‑ seasonable temperature.

Forecast reliability : fairly good until Monday ‑ poor thereafter.

ReportsAs a reminder, today in Chamonix, the sun rises at 05:44:56 and goes down at 21:16:04.
45.55 N 6.51 E - Altitude 1020 m
May 21 - 08:00
Temperature +9°C
Relative humidity 85%
Wind 0 km/h
Sea level pressure 1016 hpa - rising slowly
Pressure at 1042 m 899 mb
Precipitation last 6h 0.0 mm
Skies partly cloudy - some cumulus, 2400-2700 m
Visibility 55000 m
Altitude 3845 m
May 31 - 07:00
Temperature -9°C
Wind NNW 5 / 15 km/h
Altitude 2250 m
May 31 - 06:00
Snow depth 48 cm
Wind 10 km/h
Gusts 20 km/h
Temperature +3°C