Copy&Paste? Hot, sunny and -once established- good thermals with a high cloudbase. Overdevelopments are to be expected in a similar pattern as today.
Synopsis:
Without surprise, the heat-dome is persisting over the Pyrenees. At the upper levels, the geopotential height is slightly decreasing, while at the surface level, the high pressure is centered far north east of the area, leading to the persisting easterly barrier-jet in the lower layers of the French Pyrenees.
Details:
Hot and sunny weather. Some thin cirrus cloud can move over the Pyrenees, but they shouldn’t significantly impact insolation. Temperatures are not changing significantly and can again easily reach 35°C+ in the flats. 0°C-isotherme remains around 4500 MASL.
Thermals:
For those who are not fortunate enough to start in the high mountains, a rather good gradient will allow thermals to from already during the forenoon, starting around 11:00 LT. In the middle and low mountains, an inversion around 1500 MASL is present, which is only disappearing towards 12:00 LT. In the afternoon, again widespread good gradients with good thermals and cloud base around 4100 MASL in the high mountains and around 3700 MASL over the Spanish foothills are forecasted. During the afternoon, the best climb rates are still in the layers around 3000 MASL, however the gradient in the lower promises slightly better climb rates below 2500 MASL than today.
Again overdevelopments in the second half of the afternoon are possible and are most likely in a similar pattern as today. Areas favorable for overdevelopment are convergence zones of northeasterly winds with the valley winds and areas with slightly more humidity.
Winds:
Except the thermic valley wind systems, easterly winds still prevail for most of the course line. Their strength is strongly dependent of the location. In the lower layers along the French foothills, the easterly wind can be moderate, locally even strong. In higher altitudes, the easterly flow is a bit weaker and overlapped by thermic effects, deflecting the winds more towards northeast. Nonetheless, the area around TP 5 could be influenced by quite significant headwind. In the Spanish Foothills, the wind is strongly overlapped (and in the afternoon blocked) by the thermic wind systems. The northeasterly flow at higher altitudes pushes the convergence zone along the main spine probably slightly to the south.
Generally, windspeeds are forecasted to be around 30-35 km/h in the lowest layers of the French foothills and around 10-25 km/h in the rest of the areas.
Outlook:
With the approach of the Atlantic low, wind will turn to south on Thursday, leading to an onset of slightly foehny conditions. First, only the western parts of the Pyrenees are affected, during the day the south wind is picking up also towards the western regions.
With the convergence being pushed to the north, the zones being most prone to thermic overdevelopments are also moving more towards into France. The low can also trigger some showers and thunderstorms towards noon over Cantabria, the Basque Country and Navarra, but these developments shouldn’t affect the athletes.
Generally, flying conditions remain good with a high cloud base, but becoming more and more rough during the day due to the south wind. Friday and Saturday remain under the spell of these southerly winds and some tricky foehn effects on the French side.
