Zarnitsy

Zarnitsy (Russian: Зарницы, IPA: [zɐrˈnʲitsɨ]) refers to a phenomenon of distant lightning, or sheet lightning, when flashes of light are seen on the horizon or illuminating clouds, but the actual lightning strike and thunder are too far away to be seen or heard. It is a meteorological optical phenomenon. Because the lightning itself is obscured, there is no associated thunder, leading to the popular description of "silent lightning." The flashes are caused by the reflection of lightning from clouds, dust, or other particles in the atmosphere. The phenomenon is most commonly observed on warm summer nights. The word itself is derived from the Russian word "зарница" (zarnitsa), which can mean “heat lightning” or “distant lightning”.