Transcript 16-3 Sever Weather

16-3 SEVERE WEATHER
Causes property damage and sometimes DEATH!!!
WHERE ANY OF YOU AFRAID OF
THUNDERSTORMS WHEN YOU WERE LITTLE?
Did your parents/someone tell you something interesting to get
you not to be afraid of these??
THUNDERSTORMS
27 things have to align in order for this to
happen
 Small intense weather that produces STRONG
winds, HEAVY rain, LIGHTNING, and THUNDER
 Can occur along cold fronts
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Warm and moist air near Earth’s surfacesunstable atmosphere can cause it
 Atmosphere
is unstable when warm air is rising with
cold air surrounding it
 Warm air reaches the dew pt—form cumulus clouds
 Can form dark cumulonimbus cloud
LIGHTNING
Electric discharge that occurs between a
positively charged area and negatively charged
area
 Thunderstorms are very active electrically


Can happen
 Between
2 clouds
 Between Earth and Cloud
 2 parts of the same cloud
Lightning strikes energy is released
 Energy is transferred to the air + causes the air
to expand rapidly + send out sound waves

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Causes THUNDER
 Sound
that results from the rapid expansion of air
along the lightning strike
SEVERE THUNDERSTORMS
produces either—high winds, hail, flash floods,
+ tornadoes
 Flash flooding-leading cause of weather-related
deaths!!!!!!!!!!
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Lightning happens during ALL thunderstorms
 Will
start forest fires
 Killing and injuring hundreds of people a yr in the
US
TORNADOES
Happen in only 1% of all thunderstorms
 Small, spinning column of air
 high wind speeds + low central pressure
 touches the ground

Starts out as a funnel cloud pokes through the bottom of a cumulonimbus
cloud—
 hangs in the air—
 funnel cloud becomes a tornado
 (when it make contact with the surface/land)

TWISTS OF TERROR
75% of the world’s tornadoes occur In the US
 Happen in spring and early summer
 Have cold, dry air from Canada-meets
warm/moist air from the Tropics

Path of destructions can be wide range- few
miles to hundred
 Only last a few minutes with tons of destruction
 Winds
 uproot
trees,
 destroy buildings,
 pick up vehicles/homes—
 throwing them into air
HURRICANES
Large rotating Tropical weather system-has
strong winds
 Most powerful storms on Earth
 Can be called typhoons and cyclones

Can very in range of size
 Occur in the 5-20 degree latitude in both
hemispheres

 Needs
warm water to occur
HOW A HURRICANE FORMS
Begins as a group of thunderstorms—moving in
tropical ocean
 Winds from 2 directions meet-cause storm to
spin

 Northern
hemisphere-move counterclockwise
 Southern hemisphere- move clockwise
Energy comes from condensation-turn to water
vapor
 Warm water-helps fuel the storm
 Water is evaporating-gives it fuel

Will continue to grow-when over the warm
ocean
 As it moves to cold water + land-losses energy

DAMAGE CAUSED BY HURRICANES
High speed winds-knock down trees, electrical
poles, damage/destroy homes, etc.
 Flooding damage
 Storm surge-wall of water that builds up in
ocean-crashes to the shore

 Property
 Death
damage
SEVERE WEATHER SAFETY
Listen to weather—TV +Radio
 Know when it is getting worst-take safetycoverage
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THUNDERSTORM SAFETY
Lightning-very dangerous, will be attracted to
tall objects
 Outside- stay AWAY from TREES
 Open land- crouch down
 Stay away from bodies of water
 If strikes you can die or be hurt
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TORNADO SAFETY

Watch
 Weather
alert that let people know it a tornado MAY
happen
 Weather looks like one could occur
 HASN”T happened yet
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Warning
 Weather
alert that let people know that a TORNADO
has been SPOTTED
 Find shelter Quickly
 Basement/cellar
 Windowless room-center of the building
 Outside lie down in large-open field or DEEP ditch
FLOOD SAFETY
Watches and warnings have for these
 Flash floods-hardly any warning can be given
 Get to high place-wait out the flood
 STAY OUT of FLOODWATERS
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 Water
will move faster than you think
HURRICANE SAFETY
EVACUTE the AREA
 Have a disaster kit-water and food for several
days
 Put Plywood in front of windows
 STAY INDOORS
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THE END