Mountain valleys heat up faster than the plains, so air flows up the valleys in the afternoon and back down at night. XCviewer computes these breezes from the terrain and the sun: the sunlit area upstream, the depth and shape of the valley and the time since sunrise. Compared with high-resolution weather models (MeteoSwiss ICON-CH1, DWD ICON-D2) in 17 Alpine valleys, the direction is right within ±45° on 78 % of sunny afternoons.
What you get
- Arrows showing breeze direction and strength, valley by valley.
- Day and night regimes, starting once the morning sun has broken the cold pool.
- Breezes fade automatically when the wind at ridge level is strong.
- An optional input to the route optimizer for glides along the valleys.
Why it matters for you
- Know whether the valley will push you home or block your glide.
- Choose landing fields with the breeze in mind.
- Understand the wind at takeoff before you get there.
Related 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.