This is a collection of links for forecasting thermals for paragliders. Based on my notes from a course by No guarantees of correctness, completeness etc!

  • Emagrams (e.g. Payern): old, inprecise, complicated to read ==> don’t use anymore, there are more modern tools available
  • The only manual thermal forcast in Switzerland is from Schaenis Soaring

RASP (Regional Atmospheric Soaring Predictor)


  • more precise for Alps, prefer over RASP when in the Alps
  • uses COSMO-7 model (7km grid)
  • offered by these websites
      • costs CHF 65 per year (but well worth it!)
      • very precise
      • lists the expected vertical thermal velocities for location and time of day/temperature:
        • velocity number should be 4 or larger (4 * 0.5 m/s = 2 m/s), people use this to look at the forecast for their starting position and wait for takeoff until the precise time or temperature when the number is 4 or larger

Other Stuff

  • people used this in the old days
  • study pilot tracks at
  • click on “Show Hotspots” and the download hotspot data to vario
  • for wind forecast use the 800m-above-ground instead of the 10-m-above-ground as this is more relevant for us