Transcript WEATHER

Types of Severe WEATHER
and Fronts
Objective:
Can I use meteorological data to
predict weather?
Weather
A daily change in the condition of the
atmosphere
Our Sun
The sun
provides the
that is
responsible
for all of
Earth’s
weather
Types of weather
Severe weather
Tornado
• A severe storm
that forms as
rapidly rotating
funnel cloud.
• The peak
season in
Tennessee is
March – May
Tornadoes
• Only happen in 1% of all
thunderstorms.
• Small, spinning column of
air that has high wind
speeds and low central
pressure and that
touches the ground.
• http://youtu.be/3Qu9wR0
3GVA
Formed from
Cumulonimbus clouds
WEIRD SCIENCE
• People have reported seeing “naked” chickens
after tornadoes strike rural areas. A likely
explanation is that tornadoes cause chickens to
shed their feathers, or molt. Chickens often molt
when attacked. As the chickens molt, the strong
tornadic winds blow their feather off.
Cool Facts
• About 75% of the world’s tornadoes occur
in the US.
• Usually a tornado starts off as a white or
gray cloud but if it stays around for a while,
the dirt and debris it sucks up eventually
turns it into black one.
• The United States have an average of 800
tornadoes every year .
• A Tornado in Oklahoma once destroyed a
whole motel. People later found the motel’s
sign in Arkansas.
Tropical Storms/Hurricanes
• Low pressure storm
with high winds from
the ocean
Categories of Hurricanes
1. 74-95 mph – minimal hurricane
2. 96-110 mph – moderate hurricane
3. 111-130 mph – extensive hurricane
4. 131-155 mph – extreme hurricane (Andrew)
5. >155 mph – catastrophic hurricane
Hurricanes
• Large, rotating tropical weather system.
• It begins as a group of thunderstorms moving
over tropical ocean waters.
• The source of energy is the evaporation of ocean
water.
• As the warm, moist air rises, the water vapor
condenses and releases large amounts of
energy.
• Catastrophic hurricane video:
Cool Facts:
• Hurricanes are the most powerful storms on
Earth.
• In the Pacific Ocean, Hurricanes are generally
known as typhoons. In the Indian Ocean they
are called tropical cyclones.
• Hurricanes are the only weather disasters that
have been given their own names.
• Hurricane season is from June to November
when the seas are at their warmest and most
humid, which are ripe conditions for a hurricane
to develop.
Fronts
• The point where two air masses meet
• Causes change in weather
Warm Front
• Warm air mass
• Will rise over cool air mass and gradually
replaces the cold air.
• Cause light rain followed by hot humid
weather
Cold Front
• A cold air mass
• Cold front will push under warm front
• Causes severe weather- heavy rains and
thunderstorms
• Followed by cool weather
Occluded Front
• Forms when a warm
air mass is caught
between two colder
air masses.
• Has cool
temperatures and
large amounts of rain
and snow.
Stationary Front
• Forms when a cold air
mass meets a warm
air mass. Both air
masses do not have
enough force to life
the warm air mass
over the cold.
• Days of cloudy, wet
weather.
Review Questions
1.Can you show me a cold front on
this map?
2. Can you find a warm front on this
map?
3. Can you find the occluded front
on this map?
4. Can you find the stationary front
on this map?
5.What type of weather is the
northeast having?
6. Sharon woke up on a sunny morning and ate
breakfast. Then she looked outside and saw
tall, quickly-forming clouds. The clouds looked
ready to rain. When she turned on the TV, she
saw just what she thought--a forecast for
sudden rains. What most likely caused the
change in weather?
A. lack of wind
B. an expanding warm air mass
C. a warm front overtaking a cold air mass
D. a cold front overtaking a warm air mass
Storm Chasers
• http://ultimatechase.com/
Review:
1.What type of weather is the
northeast having?
2. Sharon woke up on a sunny morning and ate
breakfast. Then she looked outside and saw
tall, quickly-forming clouds. The clouds looked
ready to rain. When she turned on the TV, she
saw just what she thought--a forecast for
sudden rains. What most likely caused the
change in weather?
A. lack of wind
B. an expanding warm air mass
C. a warm front overtaking a cold air mass
D. a cold front overtaking a warm air mass
3. If the wind was 135 mph what
classification of hurricane would it be
4. Which of the following instruments
measures air pressure?
a. thermometer
b. barometer
c. anemometer
d. windsock
5. On a summer evening, a barometer
reading shows a gradual increase in air
pressure. The humidity is 80%. The
thermometer reading is slightly increasing.
Based on these data, what type of weather
should be expected for the next day? Why
Clear and Sunny
6. A student observes a clear sky and a
temperature reading of 35 Celsius at 8:00
a.m. What is the most likely prediction
about the day’s weather?
a. the day’s weather will
be cold
b. the day’s weather will
be rainy
c. the day’s weather will
be hot
d. the day’s weather will
be snowy
7. A meteorologist used radar to analyze the
wind during a storm in the central plains of
the United States. The winds were
measured at 145 miles per hour and were
moving in a circular pattern. According to
the data, which event was the
meteorologist most likely observing?
a. tornado
b. lightning storm
c. rainbow
d. cloud formation
•
8. “The weather tonight will be dominated
by air movement that is caused by air
moving from areas of high to low
pressure.” This describes:
a.
b.
c.
d.
Blizzard
Warm front
Tornado
Wind
9. “Next week, you can expect this warm air
mass to meet this cold air mass over the
southern part of the state and bring rain
and snow.” This best describes:
a.
b.
c.
d.
Cold front
Warm front
Occluded front
Stationary front
10. What type of weather will a warm front
bring with it?
a. Cold and sunny
b. Cold and rainy
c. Cold and snowy
d. Sunny