Shelf cloud
A shelf cloud is a deep, horizontally aligned arc cloud in the shape of a wedge, which occurs less often with cold fronts , but above all in connection with thunderstorms and especially gust fronts . There it has a direct connection to the thunderstorm cell or other mother clouds (which distinguishes them from the much rarer roll clouds ) - and is due to their front or side spreading front. A shelf cloud is created by the downdraft of such a thunderstorm cell. At the outer edges of a shelf cloud, upward movements can often be observed, whereas more turbulent conditions can be seen at the bottom.
It can happen that a shelf cloud is confused with a wall cloud , but this is more in the lower or rear area of a thunderstorm.
Shelf Cloud is an internationally recognized Anglicism in meteorology, whereby the vague term of the gust roller is common in German-speaking countries .
Web links
- Gust roller in the weather dictionary of the German Weather Service
- Gust roll over Saskatchewan - Astronomy Picture of the Day from January 22, 2008.