CHAPTER 3, SECTION 2: STORMS
STORM- violent disturbance in the atmosphere caused by a change in ________________________
1) THUNDERSTORMS: heavy rain storms accompanied by thunder and lightning
A) CHARACTERISTICS
i)
gusty winds, heavy rain, hail, thunder, lightning
B) HOW THUNDERSTORMS FORM
i)
In thunderheads- large ___________________________ clouds
ii) Warm, humid air is forced _____________ at a cold front. This air rises rapidly and cools to form
cumulonimbus clouds.
iii) Occur mostly during the _______________ and __________________months.
iv) Strong upward and downward winds are produced called ________________ and
__________________. This produces bursts of wind called _________ ___________, which can
cause airplane crashes/accidents.
C) LIGHTNING AND THUNDER
i)
During a thunderstorm, areas of _______________ and _____________ electrical charges build up
in storm clouds. There are many collisions of many small bits of ice which create an electric charge.
ii) ________________________ is a sudden spark, or energy discharge, as these charges ________
between parts of a cloud, between nearby clouds, or between a cloud and the ____________.
iii) Lightning bolts can heat the air to as much as ________________ degrees Celsius.
iv) When this air heats, it ___________ suddenly and explosively. This produces a loud sound know
as __________________.
v) Because light travels ____________ than sounds, you see lightning before you hear thunder.
D) THUNDERSTORM SAFETY
i)
Avoid touching ____________ objects because they can conduct _______________ into the body.
and telephones or electrical appliances
ii) Stay out of open areas, away from tall objects such as trees.
2) TORNADOES: A rapidly whirling, ________________ cloud that reaches down from the storm cloud to
touch the Earth’s surface.
i)
If a tornado occurs over a lake or ocean, it is called a __________________.
B) CHARACTERISTICS
i)
develop in low, heavy _________________ clouds
ii) Usually only last about _________ minutes or less.
iii) wind speed- up to _________ kph (259 mph)
iv) Only a few hundred meters across
C) HOW TORNADOES FORM
i)
cold, dry air (CP) mass meets warm, humid air mass (MT)
ii) cold air moves under warm air, which rises
iii) creates a vortex, with high winds
iv) They occur during ___________ and __________ months, often in the late __________________
when the ground is warm.
v) Tornadoes are most likely to occur between 3 p.m. and 9 p.m.
vi) They mostly occur in “_________________ ___________________”- Great Plains states
(1) Texas, Oklahoma, Kansas, Nebraska
vii) ________________________________ has more tornadoes than anywhere else in the world
D) TORNADO SAFETY
i)
Damage is caused mostly by the strong winds and flying debris
ii) Measured by the ______________________ Scale - F0-F5
iii) Tornado ______________- tornadoes are possible in the area
iv) Tornado _____________- a tornado has been seen in the sky
v) Move to a safe area- basement of a well built building
vi) Stay away from windows and doors
vii) Lie on the floor under a sturdy piece of furniture
viii) Outside? Move to a ditch or building
3) HURRICANES: a tropical storm that has winds of __________ kph (74 mph) or higher
A) CHARACTERISTICS
i)
Form in the south Atlantic and Eastern Pacific Oceans
ii) high winds from 119-250 kph (74-155 mph)
iii) size in diameter- typically ______________ km (342 miles) across
(1) In the Atlantic Ocean, Gulf of Mexico, and the Eastern Pacific Ocean, they are called
hurricanes.
(2) In the Western Pacific Ocean, they are called _____________. In the Indian Ocean, the Bay of
Bengal, and Australia, these types of storms are called __________________.
B) HOW HURRICANES FORM
i)
Hurricanes only form over really warm ocean water of 80°F or warmer.
ii) Hurricanes that hit US form in the ________________ Ocean north of the equator in
______________, ________________, or October.
iii) Begins over water as a low-pressure area, or ______________________ __________________
(1) tropical depression (<73 mph) tropical storm (40-73 mph) hurricane (74- 155 mph)
iv) Hurricanes spiral inward toward the area of low pressure in a ___________ ___________ direction.
v) Hurricanes typically form between 5 to 15 degrees latitude north and south of the equator. The
_______________ ____________ is needed to create the spin in the hurricane and it becomes too
weak near the equator (because of the doldrums), so hurricanes can never form there.
vi) The center of the storm or "_________" is the calmest part. It has only light winds and fair weather.
C) HOW HURRICANES MOVE
i)
Each hurricane usually lasts for over a ___________, moving 10-20 miles per hour over the open
ocean.
ii) Hurricanes from South Atlantic are steered by the ______________ _____________.
iii) After a hurricane passes over __________, it loses energy and strength and will slow down.
D) HURRICANE DAMAGE
i)
strong winds, high waves, severe flooding
ii) _____________ _______________- unusually high water caused by winds during a storm
E) HURRICANE SAFETY
i)
A hurricane ___________ is an announcement that hurricane conditions are possible. People
should prepare to evacuate.
ii) A hurricane __________________ means that a hurricane is expected. Leave the area
immediately or stay towards the interior of a building.
4) WINTER STORMS: Snow falls when humid air cools below freezing ( ____°C)
A) CHARACTERISTICS
i)
Can block roads, trap people in their homes, make it hard for emergency vehicles to move
ii) Extreme cold can damage ___________ and cause water pipes to freeze and burst
iii) High winds, dangerous temperatures, Blowing snow = low visibility
B) LAKE EFFECT SNOW
I)
In the fall and winter, the land near the ___________ ____________ cools faster than the water in
the lakes
(1) Cold, dry air masses pick up water vapor and heat from the warmer lakes
(2) When the air mass reaches the other side of the lake, the air rises and cools again- forming
clouds and causing snow around the lakes to fall
C) SNOWSTORM SAFETY
I)
Find shelter from the wind
II) Cover exposed parts of the body
III) Stay dry
IV) In a car? Keep the engine running and clear snow away from exhaust