ESS5
Prof.
Jin-Yi Yu
Severe
Thunderstorms
qOccur when winds exceed
93 km/hr (58 mph), have
large hailstones (1.9 cm;
0.75 in) or produce tornadoes.
qThese systems differ
from air mass thunderstorms in that
the up and downdrafts support each other to intensify the storm.
qParticular atmospheric
conditions must persist across the
mesoscale (10-1000 km) for severe
thunderstorms to
develop.
q Atmospheric conditions supporting
severe thunderstorms include
wind shear, high water vapor
content in lower portions of the
troposphere.