Roll cloud
A roll cloud is a deep, horizontally aligned arcus cloud in the form of a roller , which occurs mainly in connection with thunderstorms and especially gust fronts , more rarely with cold fronts .
Roll cloud is an internationally recognized Anglicism in meteorology and can be translated as roll cloud , but in the German-speaking area the rather vague term gust roller is common for it. They have this name because to the observer it appears as if they are rolling across the sky and rotating around a horizontal axis. They should therefore not be confused with the much smaller and more vertically oriented funnel clouds . In addition, they are usually accompanied by strong gusts on their front side and even downbursts .
Roll clouds are quite rare and, unlike the shelf clouds related to them, have no connection to the original thunderstorm cell or other cloud formations.
A roll cloud that is particularly famous among glider pilots is the Morning Glory Cloud , which can be regularly observed in the northern Australian Gulf of Carpentaria .
