The onset of thunderstorms in northern Bohemia on Monday was accompanied by a massive rotor cloud, known as a roll cloud. The relatively rare cloud formed at a sharp temperature boundary in connection with the advancing front of a cold front.
The onset of thunderstorms in northern Bohemia on Monday was accompanied by a massive rotor cloud, known as a roll cloud. The relatively rare cloud formed at a sharp temperature boundary in connection with the advancing front of a cold front.