Meteorology Chapter 11 Review

When a cold dry air mass (cP or cA) moves over a relatively warmer body of water, such as the Great Lakes, heavy snow showers called ________ will form on the downwind shore line.

"Lake Effect Snow"

What are the 5 Air masses?

1.Continental Arctic (cA) 2.Continental Polar (cP) 3.Continental Tropical (cT) 4.Maritime Polar (mP) 5.Maritime Tropical (mT)

What five criteria are used to determine the location of a weather front on a surface weather map?

1.Significant temperature changes over a relatively short distance 2.Change in the air's moisture content 3.Noticeable shifts in wind direction 4.Pressure patterns in the isobar contours 5.Clouds and precipitation patterns

Where do dry lines most often set up?

Across the southern and central high plains

An extremely large body of air whose properties of temperature and moisture are fairly similar in any horizontal direction at any given altitude.

Air Mass

A region where an air mass will originate.

Air Mass Source Region

What type of clouds are associated with a warm front?

All forms of stratus (stratus, stratocumulus, cirrostratus, altostratus, etc)

A _______ front represents a zone where cold dry air will replace warm moist or warm dry air. Surface winds tend to be southwest to south direction ahead of the front to a west-northwest or northerly direction behind the front. Atmospheric pressure will be falling before the front arrives and start to rise after the front passes

Cold

If the coldest air is located behind the cold front, then it will be a _____ Occlusion. If the coldest air is located beneath the warm front, then it will be a _____ Occlusion.

Cold, Warm

____ air masses form over land/ice and are fairly dry?

Continental

Air mass that is very cold, dry, stable?

Continental Arctic

What is the coldest of all air masses?

Continental Arctic

Air mass that is cold, dry, stable?

Continental Polar

What does cP represent?

Continental Polar

Air mass that is hot, dry, stable aloft, unstable near surface?

Continental Tropical

A __ _____ is not a warm front or cold front, but represents a narrow boundary where there is a steep horizontal change in moisture.

Dry Line

With good upper level support, thunderstorms will develop along the ______ during the late afternoon hours.

Dry Line

_____ separate a hot dry air mass (cT) to the west from a hot moist air mass (mT) to the east.

Dry Lines

Where is the best region of development for Lake Effect Snow in relation to the Great Lakes?

Eastern and southeastern shore lines along the Great Lakes

The formation, strengthening, or regeneration of a weather front. Usually caused by an increase in the temperature contrast across the frontal boundary.

Frontogenesis

The weakening or dissipation of a weather front. Occurs when the temperature contrast across a frontal boundary weakens.

Frontolysis

What type of weather is associated with a stationary front?

It depends on the type of air mass.

What type of weather is associated with a "Warm Front"?

It varies, although they can be associated with thunderstorms.

What time of year is best for the development of lake effect snow?

Late fall to early winter

What type of pressure systems will a front come out of?

Low pressure system

____ air masses form over open water and are fairly moist?

Maritime

Air mass that is cool, moist, unstable?

Maritime Polar

Air mass that is warm, moist, usually unstable?

Maritime Tropical

In which region of the world do air masses collide and some of the world's most violent weather take place?

Mid latitudes

Are the mid-latitudes a good source region for air mass development?

No, Surface temperatures and moisture characteristics vary considerably in the mid-latitudes making this region a poor source region for air mass development.

The origin of a cP air mass that enters the U.S. is located . . . ?

Northern Canada and Alaska

When a cold front catches up to and overtakes a warm front, the frontal boundary created between the two air masses is called an _________ Front.

Occluded

Air being lifted by the process of a warm front is called what?

Overrunning

What are the 4 weather fronts and their symbols?

Stationary (alternating warm/cold) Warm (Red bumps) Cold (Blue Triangles) Occluded (Purple bumps and triangles)

A ________ front has essentially no movement. Surface winds tend to flow parallel to the front, but in opposite directions on either side of the front. Upper-level winds, for the most part, move parallel to the surface stationary front.

Stationary Front

An air mass is characterized by similar properties of ____ and ____ in any horizontal?

Temperature, Moisture

What played a role in the Grand Forks 1997 flood?

The Aleution Low was too far south, pushed moisture inward causing heavy snowfall in GF - lead to flooding

What type of weather would you expect with an "Occluded Front"?

The weather would resemble that of a warm front on most occasions, although thunderstorm activity may occur.

What types of weather events are associated with a cold front?

Thunderstorms and snow squalls

A ____ front represents the location where advancing warm, moist or dry air is replacing retreating cold air. Surface winds typically have an easterly component ahead of the front and a southerly component after frontal passage.

Warm front

A transition zone between two distinct air masses of different properties.

Weather Front

An air mass will usually move in response to the winds _____.

aloft

In order for a huge mass of air to develop uniform characteristics, its source region should be generally _____ and of _____ composition with light surface winds. Therefore, ideal source regions are usually those areas dominated by surface_____ pressure systems.

flat, uniform, high

Between which boundary will the greatest contrast between temperature and moisture occur?

mT and cP

What is the difference between a "Cold" and "Warm" occlusion?

temperature (density) of the air masses.

A _____ ______ is located in the area that separates the two different air masses.

weather front