Back to main menu  /  d1+09Z  d1+12Z  d1+15Z   /  Help and usage   /  Use the clickable blipmaps below to get the name (mouse over) or the aerological profile (click on) of the place indicated by a black small star. Surface parameters: mslp / sfc temperature / sfc dew point / sunshine   /  Wind parameters  /  thermal parameters  /  clouds parameters Quick help: The mean sea level pressure (mslp) is the atmospheric pressure at sea level (the pressure reduced to sea level). It is an important parameter for paraglider and hangglider pilots flying in the Alps. A strong (more than 3-5 hPa) transalpine (between the north and the south sides of the Alps) mslp difference can result in unsafe and turbulent flying conditions associated with foehn phenomena, especially if there is strong winds aloft. If mslp is higher on the north alpine side it is often humid and cold on this side while it is dry and relatively warm on the south side (Italy) with turbulent and strong north wind. It is exactly the opposite with high pressure on the south side. With this chart you can immediately see red-orange colour areas (high pressure) on one alpine side and blue-green colour areas (low pressure) on the other one. If you see the same colour e.g. yellow on each side of the Alps, you can conclude a weak pressure difference between these both sides and thus safe flying conditions. The chart below represents the difference of mslp at each domain's grid point regarding the refential mslp in Bern, central northern part of Switzerland. This difference has to be examined between the northern and the southern parts of the Alps. The blue areas on the alpine southern part mean that the mslp is lower than at Bern (North Foehn), the orange-red areas mean the mslp is higher (South Foehn). Area near Bern is always white of course. If there is a white, light blue or yellow area on the southern part, that means that the pressure difference between the south and the north of the Alps is weak. Aide rapide: La pression atmosphrique rduite au niveau de la mer (mslp) peut tre un facteur important pour le vol libre. Une diffrence de plus de 3-5 hPa peut conduire des conditions de vol malsaine et turbulente surtout si des vents forts en altitude sont associs (phnomnes de foehn). Si la pression est plus forte au nord des Alpes, l'atmosphre est souvent humide et frache au nord et sche, chaude et agite (turbulence et vents forts) au sud. C'est exactement le contraire lorsque la pression est plus forte au sud. Avec cette carte on peut voir immdiatement 9, 12 et 15Z, la diffrence transalpine de pression ces 3 moments. Une plage rouge-orange correspond une zone de forte pression, une plage verte-bleue une zone de faible pression. Si les plages de couleur sont identiques ou proches de part et d'autres des Alpes (par exemple jaune), la diffrence transalpine de pression est faible. La carte d'en bas reprsente la diffrence de pression (mslp) chaque point de la grille du domaine par rapport la pression rfrentielle Berne. Cette diffrence doit tre examine entre le nord et le sud des Alpes. Le sud dans les bleus signifie surpression nord (souspression sud) donc foehn du nord et inversment le sud dans les orange-rouge signifie surpression sud (foehn du sud). Sur la rgion de Berne il y aura bien sr toujours une plage blanche. Si la plage des couleurs est blanche, jaune ou bleu clair sur le sud des Alpes, cela signifie que la diffrence transalpine de pression est faible. Back to main menu    /    d1+09Z    d1+12Z    d1+15Z