Page 156 - Super Earth Encyclopedia

GRAND SLAM

MICROBURST

Strong updrafts of warm, moist air build up giant
storm clouds. But as the warm air rises through the
core of the cloud, cold air sinks through other parts of
the cloud where there is no rising airflow. Rain and hail
can chill the sinking air even further, making it heavier
so that it falls from the sky faster and faster, like an
avalanche. This is called a downburst, or microburst.
When it slams into the ground, the cold air rushes out
from the point of impact at high speed in powerful winds
that can cause serious damage. Microbursts can be so
violent that they are mistaken for tornadoes.

FLASH FLOOD

Torrential rain cascading out
of a huge storm cloud can make
rivers and streams burst their
banks. The water spills across
roads and through towns in
surging torrents. These flash
floods can carry away bridges,
destroy buildings, wreck cars,
and force hundreds of people
from their homes.

STATS AND FACTS

TIMESPAN DOWNPOUR
A microburst is
caused by a downdraft A microburst A big storm cloud
can release up to
can last from a
of cold air, which few seconds to 300,000 tons
forces winds to blow
of water in
several minutes.
EXTREME WEATHER but it can be almost WIND SPEED km/h 170 wind speeds higher than 320
torrential rain.
outward. This is the
opposite of a tornado,
A microburst can generate
as destructive.
170 mph (270 km/h).
220
270
DIAMETER
170
140
200
110
mph
ABOUT
2.5
MILES
(4 KM)
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