Saturday, July 30, 2016, 3:00 p.m. to 4:00 p.m., Zugerberg: Within a very short time, a thunderstorm cell appears seemingly out of nowhere and moves from west to east, with strong gusts in the front and showers in the back.
Every paraglider pilot knows about the danger posed by thunderstorms. That is why we keep our distance or stay on the ground when thunderstorms threaten. Weather studies and forecasts help us make decisions. Thunderstorms were also forecast yesterday, but more towards the evening:
"Mostly sunny on Saturday. Cumulus clouds, especially over the Jura. Local in the evening, widespread showers or thunderstorms overnight into Sunday. 28 to 31 degrees. Up to 24 degrees at 1000 m. Mostly light southwest wind."
On such days, the Zugerberg is recommended; you have a constant view of the Mittelland, the Jura and the foothills of the Alps from the south through the west to almost the northeast, you can see the local thunderstorm cooker, Pilatus, and have the lake as a reference for gust lines.
When I took off at around 2:50 p.m., everything looked good: the cumuli were small, some of them higher than they were wide, and in the Jura it was a bit cloudy, but the Pilatus was clear, and the lake was smooth. At around 3:15 p.m., I was quite surprised to see the cloud to the east of Lake Zug (above Gisikon-Root, roughly) and landed shortly afterwards. I was surprised because, on the one hand, it was already very dark and powerful, and on the other hand, it seemed to have appeared out of nowhere. The first rumble of thunder followed and a storm cell passed through according to all the rules of nature: gusts as the vanguard, lightning and thunder and heavy showers and winds. I was glad to be out of the air. Even more so were those pilots who landed when the first drops of rain began to fall.
Thunderstorms are difficult to predict in terms of location and time. Strong winds (like yesterday, July 30, 2016) encourage the transport of moist air and allow storm cells to grow and move rapidly. The rain radar cannot predict this. So be careful and keep your eyes wide open!
