Foehn is one of the main hazards of Alpine flying. XCviewer computes a foehn index the way forecasters do: the sea-level pressure difference across the Alps (Lugano–Zürich and Bolzano–Innsbruck) combined with the wind at 700 hPa. It also estimates lee waves from the ridge-level wind and highlights the valleys exposed to rotors. When foehn is forecast, the route optimizer warns you and cancels the valley breezes.
What you get
- North and south foehn regime with the pressure difference and the wind at 700 hPa.
- Lee-wave likelihood, wavelength and rotor risk downwind of the ridges.
- A map of the lee areas exposed to foehn turbulence and rotors.
- Automatic warnings in the route optimizer.
Why it matters for you
- Foehn days can look perfect from the valley: get the signal before you drive up.
- A free safety layer for every pilot, on every plan.
When foehn is forecast, flying in the lee valleys is dangerous. This index helps you spot the risk; it never tells you that a day is safe.
Step-by-step tutorialRead thermals, valley breezes and foehnRelated features
Route Optimizer
Place your turnpoints: XCviewer finds the best route and every climb for the day, the time and your glider.
Where to Fly: XC Zones
The cross-country potential of every Alpine valley, day by day, for your glider.
Hike & Fly Planner
Plan X-Alps style days: fly when it works, walk when it is faster, relaunch from summits.