Download Ch. 16 Atmosphere and Pressure

Name __________________________
Date _____________
Class ___________
Fronts and Storms (read pp. 596-613)
Air Masses
An __________ _____________(596) is a large body of air that
has properties similar to the part of the Earth’s surface over
which it develops. _____________(597) major types of air
masses influence the weather in North America.
_________________ _______________(597) are warm, humid
air masses that forms over the tropical Pacific and Atlantic.
_____________________ _____________(598) are cool,
humid air masses that form over the cold North Pacific and Atlantic. _______________________ _________________(598) are hot, dry air masses that form mostly in the summer over dry areas of the
Southwest and northern Mexico. _________________
______________(598) air masses from over
northern Canada and bring bitterly cold weather with very low humidity. In the continental United States,
prevailing westerlies, generally push air masses from (599)____________ to _____________.
________ ___________(599) cause air masses to move north or south as they move from west to east.
Fronts
A ______________(599) is a boundary between two air masses of
different density, moisture, or temperature. A ___________(600)
front occurs when a cold air mass advances and pushes under a
warm air mass forcing the warm air mass to rise. If it is pushed up
fast enough, a narrow band of violent ___________(604) can result.
___________(601) front occurs when warm air advances into a cold
air mass it is forced up over the cold air mass. If the air is
____________(601), light rain and snow falls. _______________(601)
front occurs when a warm air mass is caught between two cooler air
masses. ______________________(601) usually drops with chance of
rain or snow. A stationary front occurs when two fronts meet but neither
________________(601). If a stationary front remains over an area, it can
bring many ______________(601) of clouds and rain.
_______________(602) are found at the center of a low pressure and are
associated with clouds, wind, and precipitation. _____________________(602) are found at the center of a high
pressure and generally cause dry, clear weather.
Severe Weather
__________________________(605) form in large cumulonimbus
clouds, also known as thunderheads. Thunderstorms cause
lightning and _____________(606) damage. Avoid places where
__________________(605) may strike or objects that conduct
electricity. ____________________(605) happens when the
negative charges (electrons) in the bottom of the cloud are
attracted to the positive charges (protons) in the ground. Thunder
is caused by lightning heating the air to over
_______________(605)°C, hotter than the sun. The rapidly heated
air expands causing an ___________________(605). ____________________(606) can form when warm,
humid air rises rapidly in a cumulonimbus cloud. Varying winds at different heights can spin the rising air
like a top. Safest place to be is a storm ________________ or ___________________(609). Tornadoes
occur more often in the United States than any other country. Weather patterns over the Great Plains result
in a ____________________ _________(607). A _____________________ ( 610) begins over warm
ocean water as a low-pressure area, or tropical disturbance. May cause flooding and wind damage.
_______________________(611) is the best course of action. Winter Storms can produce heavy
__________________(612) that can block roads and collapse buildings. If you are caught in a snowstorm,
find shelter from the wind.
WORD BANK
Cold
maritime polar
*lightning
Four
east
30, 000
Air mass
west
continental polar
front
jet streams
Storm
continental tropical
temperature
Thunderstorms
shelter
snowfall
Maritime tropical
days
flooding
Humid
tornado alley
advances
Occluded
hurricane
anticyclones
Basement
cyclones
explosion
*Lightning
tornadoes
warm
Evacuation
*words used twice