Shelf cloud
A shelf cloud is a low, horizontal, wedge-shaped arcus cloud. A shelf cloud is attached to the base of the parent cloud, which is usually a thunderstorm cumulonimbus, but could form on any type of convective clouds. Rising cloud motion can often be seen in the leading (outer) part of the shelf cloud, while the underside often appears turbulent and wind-torn. More… Cool, sinking air from a storm cloud’s downdraft spreads out across the land surface, with the leading edge called a gust front. This outflow cuts under warm air being drawn into the storm’s updraft. As the lower and cooler air lifts the warm moist air, its water condenses, creating a cloud which often rolls with the different winds above and below (wind shear).
Whale’s mouth over Venice by Francesco Dalla Stella
Another hunt ended with the sight of this imposing “whale’s mouth” with some attempt to create a shelf cloud at its leading edge at the head of an intense storm line descending from the preAlp towards the coast
Squall line approaching Piombino by Samuele Montedoro
Possibly the final squall line of the 2020 storm-chasing season
Before the storm by Francesco Gennari
Shelf cloud of a storm arriving to the Romagna Riviera on a hot July morning. A seagull rests on the rocks before the storm
Amazing shelf cloud above Cesena by Francesco Gennari
A strong and very fast MCS structure near Cesena, Emilia Romagna, during a summer outbreak
Amazing shelf cloud in southern Germany by Andreas Feichtmeier
Shelf cloud north of Kempten in south Germany
Velebit behind a shelf cloud by Danijel Palčić
The largest mountain range in Croatia disappears behind a shelf cloud
Afternoon shelf cloud in Canelones by Mati Mederos
Shelf cloud in Canelones, Uruguay