Fairly weak high pressure ridge Canary Islands to Alps with fairly mild subtropical spur high up, drifting east and allowing for a fair post‑summer Wednesday. • Powerful low system currently developing from Southern Greenland and expected to reaching Ireland with 985 minimum by Thursday evening; linked cold front, not really active, should cross over Western Alps earlier, probably in the afternoon. • Well unsettled period expected thereafter, possibly starting up with foehn gale by Friday afternoon. Precipitation getting heavier during the night to Saturday, going along with temperature drop that would set rain‑snow limit towards 1600 m in the morning. • Uncertain outlook in detail from Thursday noon.
Fair weather ‑ quite chilly at first ‑ pleasant warmth in the afternoon
SKY CONDITION : clear or partly cloudy ‑ some early morning high cloud ‑ tiny cumulus cloud later. Period of sunshine close to 90%.
PRECIPITATION : none.
WIND - ground level : calm or variable light ‑ occasionally SW.
TEMPERATURE : low +1°C - high +20°C - temperature inversion toward 1500 m early in the morning.
ISOTHERM 0°C : 3400 ‑> 3500 m.
ROAD CONDITION : snowfall above 1200 m - melting snow on roadways (Saturday, 08:00).
Clear, becoming partly cloudy ‑ rather cool towards dawn
SKY CONDITION : clear in the first part of the night ‑ thin high cloud from west later, thickening somewhat before dawn ‑ fairly good radiation condition ‑ iso 0°C dropping towards 3300 m.
PRECIPITATION : none.
WIND - aloft : W light ‑> WSW moderate.
TEMPERATURE : low +3°C.
Morning sunny spells ‑ almost inactive cold front coming in later ‑ windy high up
SKY CONDITION : partly cloudy to cloudy in the morning, thickening high cloud from southwest ‑ becoming quickly mostly cloudy in the afternoon. Period of sunshine close to 30%.
PRECIPITATION : some shower in the afternoon ‑ rain‑snow limit towards 2400 m, dropping ‑ amount of water in the valley : ± 1 mm.
WIND - aloft : WSW moderate ‑> SW moderate to strong.
TEMPERATURE : low +2 °C - high +14°C.
Foehn generated sunny outbreaks and rolling cloud from south ‑ severe gale
SKY CONDITION : cloudy with foehn generated sunny outbreaks ‑ becoming mostly cloudy to overcast later. Period of sunshine close to 25%.
PRECIPITATION : heavy shower in the evening with possible local thunderstorm ‑ rain‑snow limit dropping towards 1800 m during the following night.
WIND - aloft : SW strong ‑> SSW severe gale ‑ very strong foehn risk in the valley later.
TEMPERATURE : rising lows.