A Roll Cloud Reaches the North-West Istrian Coast, Activated by Fresh Masses Descended (Downdraft) by the Strong Thunderstorm on the Trieste Gulf; Črnotiče Karst Ridge, Koper, Istra/Istria, Slovenija
08-September-2022
"Roll cloud" is a low, elongated cloud, which is part of the numerous types of accessory clouds of a storm front (Fractocumulus genus), which signals the "gust line", or the change of wind just before the arrival of precipitation, along the virtual lines of air convergence and thermal discontinuity.
On the sea, as on the plains, the Roll cloud, formed by colder and denser air than the one it finds, literally rolls (and rolls up) at low altitude, skimming the ground, which unlike other frontal clouds, can sometimes move away from the storm that generated it for many tens of kilometers, thus resulting, in such cases, a harmless windy residue, but, as in this case, in the interaction with a more marked orography it tends to become irregular and therefore to dissolve.
The Roll cloud in the photo was formed on the sea by condensing the cooler air descended, through rain and hail, from the considerable T-storm that brought the water of the whole month in less than 3 hours on all the areas facing the Gulf of Trieste.
A Roll Cloud Reaches the North-West Istrian Coast, Activated by Fresh Masses Descended (Downdraft) by the Strong Thunderstorm on the Trieste Gulf; Črnotiče Karst Ridge, Koper, Istra/Istria, Slovenija
08-September-2022
"Roll cloud" is a low, elongated cloud, which is part of the numerous types of accessory clouds of a storm front (Fractocumulus genus), which signals the "gust line", or the change of wind just before the arrival of precipitation, along the virtual lines of air convergence and thermal discontinuity.
On the sea, as on the plains, the Roll cloud, formed by colder and denser air than the one it finds, literally rolls (and rolls up) at low altitude, skimming the ground, which unlike other frontal clouds, can sometimes move away from the storm that generated it for many tens of kilometers, thus resulting, in such cases, a harmless windy residue, but, as in this case, in the interaction with a more marked orography it tends to become irregular and therefore to dissolve.
The Roll cloud in the photo was formed on the sea by condensing the cooler air descended, through rain and hail, from the considerable T-storm that brought the water of the whole month in less than 3 hours on all the areas facing the Gulf of Trieste.