ESS124
Prof.
Jin-Yi Yu
Flash Floods of the
Desert Southwest
•Most of the year, the southwest deserts of the US are hot, dry,
and sunny and
receive very little rainfall.
•In the summer months, thunderstorms develop over the
southwestern US following
the onset of the North American Monsoon.
•These thunderstorms can produce short-duration, very high
intensity rainfall.
•In much of the desert, rain runs off quickly and channels
rapidly into very narrow
canyons.
•Within the canyons, the height of the water often builds
rapidly, forming a wall
of water that roars down the canyons with no warning.