TODAY – SATURDAY MAY 18 2013
Sunny spell, then thick high cloud – f?hn wind gale, locally, in the afternoon
SKY CONDITION : bright sunny spell early in the morning, then thick high cloud running over from the south. Period of sunshine close to 35%.
PRECIPITATION : none before the evening.
WIND - ground level : light to moderate f?hn wind at first, increasing – locally gale force in the afternoon – decreasing later.
WIND - mid mountain : SE light und moderate – strong at times in the afternoon.
WIND - high mountain : SSW -> S moderate to strong – strong at times.
TEMPERATURE : low +1°C - high +17°C.
ISOTHERM 0°C : 2200 -> 2800 -> 2200 m.
ISOTHERM -10°C : 3800 -> 4400 -> 4000 m.
F?hn wind ending – precipitation beginning – disturbance crossing over – getting cooler
SKY CONDITION : mostly cloudy, then overcast.
PRECIPITATION : running over from the south early in the night – locally heavy towards the latter part of the night – rain-snow limit towards 2000 m dropping towards 1500 m.
WIND - aloft : S moderate to strong -> SE moderate.
TEMPERATURE : low +5°C.
SUNDAY MAY 19
Cool – showers, then sunny spells – instability resuming in the afternoon
SKY CONDITION : overcast or mostly cloudy early in the morning – sunny spells spreading out towards the middle of the day – considerable cumulus cloud growth over the slopes in the afternoon. Period of sunshine close to 25%.
PRECIPITATION : remaining precipitation early in the morning, then dry – locally heavy showers resuming towards the latter part of the afternoon – rain-snow limit towards 1600 m.
WIND - aloft : SE moderate -> variable light -> SW light to moderate.
TEMPERATURE : low +5 °C - high +12°C.
Low pattern over Western Europe. Minimum 1002 hpa, close north to the Pyrénées, linked to an altitude cold drop. The whole system is filling while drifting north, but still driving a humid and unsettled southerly stream towards the Alps with a locally gale force temporary f?hn wind effect over the northern slopes today. Very active rainy disturbance then crossing over the area overnight. Further outlook, still uncertain by now, doesn’t show any noticeable long lasting improvement before the middle of the week.