GENERAL SYNOPSIS- Altitude : High over Western Europe.Weak North-East then North-West flow over the Alps at 5500m. Variable winds under 3500m ( see chart 3000m ).- Surface : High 1025hPa over the Atlantic ocean, still extending over Western Europe but slowly weakening.Consequently, hot and sunny weather in the French Alps, perhaps with some late afternoon thunderstorms over the highest summits close to the Italian border.
QNH 1017hPa FL 75 2320m FL 115 3540m FL 195 5980m
AIR MASS / DEVELOPMENT OF CONVECTION SOUTHERN ALPS- St-Auban sounding
:. Nocturnal inversion under 1100m, then a favourable layer for convection
up to 3000m. Moisture is more important than yesterday and allow Cu to
form, first around 2500m, reaching 2800m over mountains in St Auban area,
and 3400m over higher mountains with a summit at 2000m.- St-Crépin
sounding : lowest layers rather stable and moist under 2500m, then a favourable
layer up to 3100m. Between 3100 and 3800m, the atmosphere is moderatly
stable, and the thermals will be slow. Inversion layer blocking convection
at 3800m. Cumulus bases should be at that level in les Ecrins and Bonneval
area.
ISO 0°C 3700m ISO -10 °C 5100 m
Favourable elements :- good convection in high mountain, with 1 or 2
small Cumulus, base above 3800m. - light winds and « normal »
breezes... convergence lines ( NE wind and breezes, and also sea breeze
limits in the South of St Auban ).. Unfavourable elements
:- risk of Cb and thunderstorms close to the Italian border.- may be NE
wind in the passes as Montgenèvre.- very stable and blue thermals
close to Rhone valley, with a persisting light North wind.
Outlook for tomorrow :Weak winds and rather flat pressure fields. Good
gliding day, but an increasing probability of thunderstorms.
Visit Philippe de Péchy's "Vol à Voile" (Soaring) server : infos, ad's, glider pictures, GPS turnpoints coordinates, competitions results and an unofficial ranking of all glider pilots in the world.
Other sites of soaring interest : |
|
Web page by Denis
Flament (from Nogaro
aeroclub) consulted times since 13-Jun-97 updated : 13-Jun-97 |