Multicell to Supercell
from multiple updrafts to a single updraft

Viewed from the west, this late afternoon Kansas storm has subtle indications of being multicellular. Can you see the two major updraft areas? Note the dark, rain-free bases beneath each updraft, with a gap between the bases. You cannot always discern between storm types by visual observations. Radar usually is the best tool for that purpose, but in many cases the visual appearance will yield important clues.

Photograph by Hoadley

This is the same storm (continued from the multicell storm page) complex less than one our later. The multicell storm apparently has evolved into a complex with one dominant updraft. The storm has become a supercell; note the rope-like tornado to the immediate right of the sun-lit precipitation shaft. The tornado is occurring beneath the updraft on the storm's southwest flank, the most likely location for supercell tornadoes.

Photograph by Hoadley

The storms we have seen lead us to ask several fundamental questions: What environmental factors influence the type or types of storms and the intensity of severe weather that occur on a given day? And why does a storm sometimes evolve from one type to another?

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Credits and Acknowledgments for WW2010.
Department of Atmospheric Sciences (DAS) at
the University of Illinois at Urbana-Champaign.