VALID FROM : THURSDAY JULY 29 2010 -- UNTIL : TUESDAY AUGUST 03 2010
GENERAL SYNOPSIS
High 1027 hpa, northeast of Azores. Low 1000 hpa, Eastern Baltic Sea, drifting west while deepening. Westerly, then northwesterly stream in-between. Altitude cold drop over Western Germany and Switzerland, drifting towards the Genoa Gulf, increasing instability and causing locally heavy precipitation over the northern slopes of the Alps. Improving gradually overnight.
TODAY - THURSDAY JULY 29 2010
Very unsettled - locally heavy showers - improving towards the evening
SKY CONDITIONS (cloud - sunshine) : mostly cloudy to overcast - cloudy at times with fleeting sunny spells - spells spreading out towards the evening - period of sunshine close to 20%.
PRECIPITATION : frequent showers in the morning, becoming scattered, locally heavy with thunderstorm - rain-snow limit dropping towards 2500 m.
WIND
-
ground level : variable light.
-
mid mountain : W -> NW light.
-
high mountain : W moderate to strong -> NW moderate.
TEMPERATURE : min +13°C - max +18°C.
ISOTHERM 0°C :
3300 -> 2800 m.
ISOTHERM -10°C :
5000 -> 4600 m.
OVERNIGHT
Cloudy, then partly cloudy and cool
SKY CONDITIONS (cloud) : cloudy in the first part of the night - becoming partly cloudy - persistent fog patches at mid-montain level likely.
PRECIPITATION : probably none.
WIND
-
aloft : NW moderate -> N light to moderate.
TEMPERATURE : +7°C.
TOMORROW - FRIDAY JULY 30
Fairly sunny - cool in the morning - milder in the afternoon
SKY CONDITIONS (cloud - sunshine) : possible low cloud early in the morning - becoming clear or partly cloudy - period of sunshine close to 80%.
PRECIPITATION : none.
WIND
-
aloft : N moderate -> NNE moderate to strong.
TEMPERATURE :
min +7°C - max +21°C.
SATURDAY JULY 31
Fair summer weather - cool in the morning - warm later
SKY CONDITIONS (cloud - sunshine) : clear or partly cloudy - period of sunshine close to 100%.
PRECIPITATION : none.
WIND
-
aloft : N moderate to strong -> NW light to moderate.
TEMPERATURE :
dropping lows - rising highs.
EXTENDED OUTLOOK UNTIL TUESDAY AUGUST 03 2010
Sunday : fairly sunny and warm - becoming sultry with possible late afternoon thunderstorm. Monday : frequent thundery shower - dropping temperature. Tuesday : fairly sunny.
Forecast reliability : poor.
Reports
Chamonix-ville
45.9 N 6.9 E - Altitude 1042 m 29 July 08:00
Temperature +13 °C Relative humidity 100 % Wind 0 km/h Pressure 1015 hpa - rising Pressure at 1042 m 896 mb Precipitation last 6h 5.5 mm Recent shower Skies overcast Visibility 5000 m
Aiguille du Midi Altitude 3845 m 29 July 08:00
Temperature -3 °C Wind WSW 30 km/h Relative humidity %
Le Lac Blanc Altitude 2330 m 29 July 08:00
Snow depth 0 cm Wind 15 km/h Gusts -- km/h Temperature +5 °C Relative humidity -- %
