Video: Massive Supercell Overtakes Beach

Massive storm supercell rapidly closing in on a beach in Helsinki Finland.

A supercell is a thunderstorm that is characterized by the presence of a mesocyclone; a deep, continuously-rotating updraft. Of the four classifications of thunderstorms (supercell, squall line, multi-cell, and single-cell), supercells are the overall least common and have the potential to be the most severe. Supercells are often isolated from other thunderstorms, and can dominate the local climate up to 20 miles (32 km) away.

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