Karkonosze

From Sniezka

very beautiful shot! looks like a tornado the clouds.

Very impressive work, Piotr! Best regards, Ruud.

Nice photo. The lenticular (lens-shaped) cloud formation downwind (farther away from the camera), with the rotor cloud upwind (closer to the camera and lower), strongly suggests mountain wave activity. These types of clouds form when moderately strong and steady wind carrying a stable airmass (one without much heat-based convective activity) crosses a mountain ridge or mountain chain. As the air is forced upward to cross over the top of the mountains, it cools, and at the altitude where the temperature drops sufficiently to reach the dew point, the water vapor component of the air condenses to form water droplets which, collectively, make up a cloud. As the air descends again on the downwind (back) side of the mountains, it warms up enough to evaporate the water droplets, and the cloud dissipates. This type of cloud constantly forms on the upwind side and constantly dissipates on the downwind side, thus seeming to hover motionless in the same location even though the wind is blowing strongly. The rotor cloud marks a boundary area of turbulence, where lower cloud rolls and tumbles. Sailplane pilots can use the powerful rising air currents on the upwind side of a mountain wave to climb to considerable altitudes, but this kind of flying is only for well-trained and experienced pilots, because the turbulent rotor and the powerful downdrafts on the downwind side of the wave are very hazardous.

thank you peter for that wonderful and complex information.. i have to read it 5 more times to understand it.

Photographically very well captured by Piotr and scientifically well explained by Peter, this dramatic view of the sky is amzing the the photo is just beautiful, exceptionally well photographed !.

Niesamowite!