Overshooting top

Overshooting tops develop on thunderstorms that have particularly strong updrafts.

Overshooting tops typically develop on Cumulonimbus capillatus incus clouds. The updraft punches through the equilibrium level (and thus the anvil), rising higher due to its momentum, despite not being buoyant anymore. An overshooting top is usually short-lived, several tens of seconds, up to several minutes. In rare cases, it may persist much longer.

overshooting-top-sunset-italy

Overshooting top on a severe thunderstorm near Ancona, north-central Italy on June 26, 2016. Note the massive updraft! Photo by Marko Korošec
 

An overshooting top, particularly a persistent one, is an indication of a potentially severe thunderstorm.

An overshooting top is difficult to see, and can only be seen on distant thunderstorms. It is readily apparent also in satellite imagery, in particular at low Sun angles (i.e. morning and, more often, late afternoon).

overshooting-top-slovenia

Overshooting top on a severe thunderstorm over central Slovenia on June 28th, 2008. Also, note the pileus/velum clouds on the updraft in the foreground. Photo by Marko Korošec
 

SEE ALSO:

Mammatus clouds