4
TYPES of
AIR MASSES
MARITIME
Maritime
Continental
Tropical
Polar
Wet, humid
[marina=boat,water]
Continental
Dry
[over the land, over the continent]
Tropical
WARM
[tropical islands are warm]
POLAR
COLD
[
lips turn purple when cold]
4 Types of
North American
Air Masses
How do scientists
classify AIR MASSES
Maritime tropical
Maritime polar
Continental tropical
Continental polar
By their:
1. Temperature
2. Humidity
(moisture)
Maritime tropical
WARM, HUMID
Affect WEST COAST
weather
COOL, HUMID
Maritime polar
West Coast more than
East Coast
Ex. OREGON
Maritime polar
Oregon/Washington
rain forest
HOT, DRY
Continental tropical
Southwest & Mexico
in the summers
Continental polar
DRY / COOL/COLD
Canada, Alaska
AIR FRONT
4
Types of Fronts
Front  mass of air
that does not mix with
another mass of air
COLD
WARM
STATIONARY
OCCLUDED
Cold air moves fast;
runs into slow warm air
TORNADO
head for
the basement!
STATIONARY
FRONT
Warm air runs into
cold air and NO
MOVEMENT happens =
stationary front
days of rain
CYCLONE
Vs.
ANTICYLONE
?? What’s the
difference
DIRECTION of SPIN
CYCLONE =
CYCLONE
Vs.
ANTICYLONE
ANTICYCLONE =
THUNDERSTORMS
BIG
CUMULONIMBUS
CLOUDS
TORNADO
Funnel shaped
Caused by:
Broken dams
Sudden storms
Ice jams
HURRICANE
Eye has calm winds
HURRICANE
WIND SPEEDS
MUST reach
119 kmph
MOVE to higher
ground!
Don’t stay in your
car!
WEATHER
ISOBARS
ANTIcyclone
weather
Isobars =
lines that show/join
places on map that
have SAME air
pressure
Clear, blue sky
DRY and CLEAR
LAKE-EFFECT
SNOW
Cold air blows over
moist lakes – then
dumps snow on land
Bring about
FRONTS
OCCLUDED
FRONT
precipitation
&
changes in weather
Occluded = blocked
off
Warm is is
BLOCKED by two
cold air fronts
Sandwiched
OCCLUDED
FRONT
El Nino
Every
2-7 years
Forms in
El Nino
Tropical Pacific Ocean
Weather Balloons
Weather Satellites
Computers
Improvement in
collecting weather
information
Meteorologist
Weatherman
Weather
Symbols
75% CLOUD
COVER
Wind speed
Weather
Symbols
End of shaft
isoTHERMs
Thermo = temperature
Shown by different color
bands on maps
Hurricanes
Vs.
Tornadoes
Hurricanes affect
greater area &
last longer
Butterfly effect
Thunderstorm
Safety
Smallest change
in today’s weather
can really throw off
next week’s
weather forecast
Stay out of water !
DO NOT hide under a
tree!
Chapter 17
Flash Cards