Geoscience Reference
In-Depth Information
sT. louIs, 1988 and 1993
Shown here are images of the junction of the Mississippi and Missouri rivers near St. Louis. To the left is the
normal stage of the rivers in 1988; to the right, a view of the same area during the flood of 1993. Increased
extreme rainfall events (for example the deluge in Nashville in May 2010 and the floods in North Korea in
the summer of 2005) are likely to become more frequent because of global change.
Storms
across the shoreline, rather than quickly
pass over it as hurricanes usually do, these
storms can create large storm surges and
threaten much property. The Ash Wednes-
day storm that struck the East Coast in
1962 and caused serious damage from Mas-
sachusetts to north Florida may have been
the region's most damaging storm of the
twentieth century.
Tropical storms form over warm tropical
waters when the temperature of surface
waters is at least 27 degrees Celsius (80 de-
grees Fahrenheit). Under these warm con-
ditions evaporation generates high humid-
ity and clouds that lead to thunderstorms,
There is considerable speculation over
whether global change, especially the
warming ocean, will lead to more frequent
storms and more intense storms. Fore-
most among the storms that will strike
and damage the North American main-
land are the tropical storms, the largest of
which are hurricanes. Other storms called
winter storms—Sou'westers on the Pacific
Coast and Nor'easters on the East Coast—
also can be very damaging. Although their
intensity may be below that of a full hur-
ricane, because they often move slowly
