Proble m Set 9 Air Masses and fronts, cyclones
1. In an exceptionally cold winter during which the Great Lakes were entirely
covered by ice, lake effect snows would be expected in extremely high frequency
2. An air mass is characterized by similar properties of _______ and ______ in any
a. temperature; pressure
b. pressure; moisture
c. winds; moisture
d. temperature; moisture
3. When continental polar air (cP) moves into western Washington, western Oregon,
and California from the east, the air mass is warmer at the surface than it was
a. the sun heats the air.
b. the air sinks, is compressed, and warms.
c. the ocean warms the air.
d. friction with the ground warms the air.
e. latent heat of condensation warms the air as it moves downhill.
4. Which air mass would show the most dramatic change in both temperature and
moisture content as it moves over a large body of very warm water?
a. Continental Tropical (cT) in summer
b. Continental Polar (cP) in winter
c. Marine Polar (mP) in winter
d. Marine Tropical (mT) in summer
5. Generally, the greatest lake effect snow fall will be on the shore of the
6. A "back door" cold front describes which of the following situations?
a. a cold front moving into Washington state from the Pacific ocean
b. a cold front moving into the desert southwest from Northern Mexico
c. a cold front that moves into New England from the Atlantic Ocean
d. a cold front that moves in a clockwise direction around a low pressure center
7. In winter, which sequence of clouds would you most likely expect to observe as a
warm front with precipitation approaches your location?
a. cirrus, nimbostratus, altostratus, cumulonimbus
b. cirrus, cirrostratus, altostratus, nimbostratus
c. cirrostratus, nimbostratus, altostratus, fog
d. cirrus, cirrostratus, altostratus, cumulonimbus
8. What type of weather front would be responsible for the following weather
forecast? "Increasing cloudiness and warm today with the possibility of showers
by this evening. Turning much colder tonight. Winds southwesterly becoming
gusty and shifting to northwesterly by tonight."
a. cold front
b. warm front
c. cold-type occluded front
d. stationary front
9. The development or strengthening of a middle latitude storm system is called:
10. Which region is not considered to be a region where cyclogenesis often occurs?
a. eastern slopes of the Rocky Mountains
b. Atlantic Ocean near Cape Hatteras, North Carolina
d. the Great Basin of the United States
e. Gulf of Mexico
11. A building anticyclone means:
a. the central pressure is increasing.
b. the anticyclone is moving toward the east coast.
c. separate anticyclones are merging.
d. the anticyclone is causing a middle latitude storm to form.
12. Northeasters (or nor’easters) are midlatitude storms commonly fo und:
a. along the Pacific coast of North America.
b. along the Atlantic coast of North America.
c. along the Gulf coast of North America.
d. along both the Pacific coast of North America and the Atlantic coast of North
13. Developing low pressure areas generally have ________ air near the surface and
_______ air aloft.
a. converging; diverging
b. diverging; converging
c. converging; converging
d. diverging; diverging
14. A person at the earth's surface beneath position 2 wo uld observe clouds overhead (at
the 500 mb level) moving from:
a. southwest to northeast.
b. northwest to southeast.
c. west to east.
d. southeast to northwest.
e. east to west.
Please answer the following in a few sentences.
1. When a warm and cold air mass collide, the warm air is forced upward. Why does this
2. Explain why the observation of a halo around the moon or sun could forewarn of the
arrival of a warm front.
3. Define the term cyclogenesis. List some of the regions in the United States where
cyclogenesis is common.