Transcript Day66

Warm- Up
1. What are the 4 types
of fronts?
2. Which type of air
mass moves faster?
3. Which direction do
the westerlies move
across the U.S.?
4. Is energy released or
absorbed during
condensation?
TOC:
177. Severe Weather
178. Hurricane WS
179. Hurricane Story
Keywords:
• Cyclone
• Thunderstorms
• Tornadoes
• Hurricanes
Mid- Latitude
Cyclone
• Most weather in US
comes from low
pressure systems
• Air moves
counterclockwise and
into center
• Most have cold front
and warm front from
the center
Cyclone formation
• Front develops first
• Front resembles a
wave
• Warm air moves
toward poles
• Cold air moves
toward equator
• Cold fronts move
faster
• Occlusion forms and
storm strengthens
Airflow Aloft
• Air in upper
atmosphere helps
form air
circulation
• Movement of air
above helps
maintain low
pressure
• Systems usually
last about a week
Thunderstorms
• Storm with
winds, thunder,
and lightning
• Usually caused
by vertical
movement of
warm air
• Generates
cumulonimbus
clouds
Thunderstorms
• 2000 at any
given time on
Earth
• 45,000 per day
• 16 million
annually
• 100,000 per year
in the US
Thunderstorms
• Warm humid air rises
in unstable
environment
• Cumulus stage
updrafts begin
• Precipitation begins
during mature stage
• Storm lightens during
dissipation stage
Tornadoes
• Violent windstorm
with rotating
column of air
• Vortex extends
down from
cumulonimbus
cloud
• 770 per year in US
Tornadoes
• Most from severe
thunderstorms
• Mesocyclone must
develop
• Mesocyclone is
vertically moving,
rotating air
• 50% of mesocyclones
generate tornadoes
Tornadoes
• Center of
tornadoes is very
low pressure
• Strength based on
wind speed
• Labeled as F0- F5
with F0 as
weakest
Hurricanes
• Whirling tropical
cyclones with
high wind speeds
• Generate huge
waves at sea and
large storm surges
on the coast
• Pose great flood
risks
Hurricanes
• Classified as
hurricane at
119km wind speed
• Need heat and
moisture to form
• Energy comes
from rapid water
condensation
Hurricanes
• Category 1- 5 with
1 the lowest
• Warm moist air
rushes in on
surface
• Air turns up at eye
• Eye is also warm
Assignment
• Complete the hurricane
worksheet
• Then use the blank map to
write a story about a
hurricane forming and
moving onto the US
• Include a chart with
coordinates that are plotted
on the map
• Also include details about
the hurricanes
development