Transcript Severe Storms

During every minute of every day, roughly 1,800 thunderstorms are
creating lightning somewhere on Earth. Though the chances of being
struck by lightning are estimated at 1 in 700,000, these huge
electrical sparks are one of the leading causes of weather-related
deaths in the USA each year with an average of 73 people killed;
about 300 people usually are injured by lightning.
As a thunderstorm grows, electrical charges build up within
the cloud. Oppositely charged particles gather at the ground
below. The attraction between positive and negative charges
quickly grows strong enough to overcome the air's resistance
to electrical flow. Racing toward each other, they connect and
complete the electrical circuit. Charge from the ground then
surges upward at nearly one-third the speed of light and we
see a bright flash of lightning.
Precipitation in the form of pellets composed
of ice or of ice and snow, occurring at any
time of the year, usually during the passage of
a cold front or during a thunderstorm. Small
hailstones have a soft center and a single
outer coat of ice. They are formed when the
surfaces of snow clumps melt and refreeze or
become coated with water droplets that
subsequently freeze.
The tornado is nature's most
violent wind. An average of 1,000
of these vortices spin up beneath
thunderstorms year round in the
USA and can generate wind
speeds faster than 250 mph, at
times devastating whole
communities.
Tornadoes have struck every U.S. state, including Alaska and
Hawaii. But most tornadoes form in a belt from Nebraska
southward through central Texas known as Tornado Alley and in
the Southeast. Wind speeds in tornadoes can vary from 72 to
almost 300 mph. Fortunately, only 2 percent of all tornadoes have
winds greater than 200 mph.
Hurricanes
Hurricanes are large low-pressure systems. Winds inside
them can blow from 75mph to over 200 mph.
As warm ocean water evaporates into the air, it rises up to the
sky and cools to it’s dewpoint temperature. Once this happens,
clouds begin to form. The more evaporation - the larger the
hurricane.
Blizzards are snowstorms and strong cold winds.
Blizzards are caused when the cold air from the Arctic
meets the warmer air from the tropics. This causes
high winds and snow.