Tornadoes

16 Pages 3908 Words

es where there is little, if any, dry air and evaporational cooling to drive downdrafts.


Relatively weak updrafts and downdrafts are found with non-severe showers and thunderstorms. The last possible combination is a storm with strong updrafts and downdrafts. These storms frequently produce destructive downbursts, hail, heavy rain, and tornadoes. As one would expect, the most severe storms, including supercells, have strong vertical drafts and occur in the most unstable atmospheres.
Supercell thunderstorms has the same size as multicell thunderstorms (20 km in diameter) but its cloud structure, air motions, and precipitation processes are dominated by a single storm-scale circulation consisting of one giant updraft-downdraft pair. The visual appearance of a supercell thunderstorm is givenin the figure below.











Supercell storms are much rarer than the single-cell and multicell storms but are much more violent and can produce damaging hail and tornadoes. Updrafts in a supercell storm are extremely strong ...