Download Storms

Storms
Notes
Thunderstorms
• A storm is a violent disturbance in the
atmosphere. Storms include
thunderstorms, tornadoes, hurricanes,
and winter storms.
• A thunderstorm is a small storm that
often has heavy precipitation and
thunder and lightning.
• Cumulonimbus clouds form on hot,
humid afternoons. They also can form
along cold fronts as warm air is shoved
upwards.
Thunderstorms
• Lightning is a sudden spark in the
atmosphere. Lightning can be from
cloud to cloud, or cloud to ground.
• The superheated air rapidly expands
and contracts, starting a wave of sound.
• Remember that light travels much faster
than sound.
Thunderstorms
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The safest place to be during a
thunderstorm is indoors.
Be mindful of flash floods.
Metal objects can conduct electricity.
Water can also conduct electricity (not the
water per se, but the stuff in the water).
Stay away from objects that can conduct
electricity during a thunderstorm.
Tornadoes
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A tornado is a rapidly spinning cloud that
reaches down to Earth’s surface.
Tornadoes usually form in the wall cloud of a
cumulonimbus formation. A tornado can be
anywhere from one mile wide, to thin and ropy.
Tornadoes typically form at the collision of the
Canadian cP air mass and the Gulf mT air mass.
Tornadoes also form more often in the United
States than anywhere else on the planet. The
majority of them form in the Great Plains’
“Tornado Alley” and the southeastern “Dixie
Alley.”
Red represents 358 tornadoes from the April 25–28,
2011 tornado outbreak. Largest outbreak in recorded
history.
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Tornadoes
A “tornado watch” is an announcement that
tornadoes are possible in your area. A
“tornado warning” is an announcement that
a tornado has been sighted or indicated by
weather radar. If a tornado warning is
issued for your area and the sky becomes
threatening, move to your pre-designated
place of safety.
If a building does not have a basement,
move to the middle of the lowest floor during
a tornado.
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Hurricanes
A hurricane is a tropical cyclone. A
cyclone has low pressure. A hurricane
has winds that are at least 119kph.
Hurricanes form in the Atlantic, Pacific,
and Indian oceans.
A hurricane draws its energy from the
warm, humid air at the ocean’s surface.
The center of a hurricane is called the
“eye.” The eye itself if calm, but the
strongest winds are found in the “eye
wall.”
Hurricanes
• Hurricanes last a week or more.
Hurricanes that form in the Atlantic
Ocean are pushed by easterly trade
winds toward the southeastern United
States.
• If you are in an area about to be struck
by a hurricane and are told to evacuate,
you must leave the area immediately.
• A storm surge is a dome of water that
sweeps across the coast where a
hurricane lands.
Hurricanes
• To evacuate means to move away from
an area.
• If you have to stay in a house, move
away from the windows.
• It is a myth that you should open
windows to prevent damage.
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Winter Storms
Every year, Rochester and Buffalo in
upstate New York receive nearly three
meters of snow.
This is due to their location in relation to the
Great Lakes.
Lake-effect snows are created when cold,
dry air from Canada blows over the Great
Lakes, picking up warm, moist air. As soon
as the air leaves the lakes, it will rise and
condense, then fall as snow <40km from the
lakes.
Winter Storms
• Blowing snows from blizzards can limit
how much you can see.
• The winds in a winter storm can also
cool off you body (hypothermia).
• Again, the best place to be is indoors
(so long as you have an operational
heating unit)