🌬️ Wind: where it comes from and how to read it
Air circulation depends on the temperature difference and air mass properties like instability, moisture, etc. The temperature difference circulation cells appear in all kind of sizes and often suppress or enhance each other. Most visible effect on us is the horizontal airmass movement along the ground surface, which we call wind. 🪂 1. Wind and Paragliding Wind has great effect on the very light paragliders with relatively big surface. Strong winds create big forces during takeoff and landing, high ground speeds and turbulence during flight. At the same time, pilots are looking for wind and air circulations to fly higher and further. Thus, studying the wind is essential for their safety and progress. First, beginners start with measuring the wind on take off, then gradually making the habit of constant observation for building mental models of the wind’s character until being able to find, explain and even predict the wind and circulations. 🧭 2. Wind Direction & Measurement Wind direction is given from where wind comes from: Pilots on the ground often help landing paragliders by showing them with one or two hands where wind comes from, especially when there is no windsock nearby. The wind strength is measured by anemometers (wind meters) in [m/s], [km/h] or [kt]. 1 m/s = 3.6 km/h = 2 knots 📈 3. Wind Classifications in Paragliding ►Calm: up to 1 m/s (forward launch; a lot of running=big take off) ►Light: 1-3 m/s; (both forward and reversed launch; still good running is needed) ►Moderate: 4-6 m/s; (reversed launch, but forward also possible, some running needed) ►Strong: 7-10 m/s; (reversed launch; only experienced pilots can fly; turbulence in the air; wind is close to paraglider air speed = chance to be lifted upward in front of the hill and blown backward after takeoff) ►Very strong: 11-13 m/s; (too strong to take off; strong turbulence in the air; landing backward; difficult to control the canopy on landing and pilot dragged on ground) ►Squall: above 14 m/s. (too dangerous to fly) 🧐 4. Wind Character ►Constant: speed doesn’t change with more than 2 m/s within 2 minutes. ►Gusty: speed changes more than 2 m/s within 2 minutes. ►Steady: direction doesn’t change more than 1 rumb (22.5°) within 2 minutes. ►Variable: direction changes more than 22.5° within 2 minutes. ►Laminar: doesn’t change speed and direction. Note: Gusty and variable winds are signs of turbulence! It is important to distinguish average wind speed from momentary gusts. For example, the gusts can make you fly backward for a moment, but if the average wind is less than your air speed, then you still go forward. If gusts exceed 100% of average wind speed, then air is probably too turbulent for beginners. The same is valid if moderate or strong wind changes its direction by more than 45°. Wind can be lifty or sinky i.e. wind is not horizontal but has upward or downward vertical component.
