Fronts

Question 1

Fronts

Answer 1

boundaries between air masses

Question 2

Four types of fronts associated with midlatitude cyclones

Answer 2

1. Cold front
2. Warm front
3. Stationary front
4. Occluded front

Question 3

What characteristics do you look out when deciding if there is a front?

Answer 3

Temperature and humidity

Question 4

How do fronts get their motion?

Answer 4

from spiraling counterclockwise about a low pressure system

Question 5

Cold front

Answer 5

mass of cold air advancing towards a warm front

Question 6

What types of air masses are generally involved in a cold front

Answer 6

Continental Polar and Maritime Tropical

Question 7

What weather does a cold front bring?

Answer 7

Heavy precipitation and rapid temperature drops (strong difference in temperature over a very short distance)

-precipitation likely to be stronger at beginning of front

Question 8

What are different colors associated with on radar?

Answer 8

Reds/Yellows = rain
Green = low precipitation

Question 9

What does a cold front look like on a radar map?

Answer 9

Intense elongated precipitation

Question 10

What does the steepness of a cold front indicate?

Answer 10

how rapidly the moist air is being lifted as the wedge advances

Question 11

What type of clouds associated with cold front?

Answer 11

Rapid lifting results in cumulonimbus clouds, so it causes intense localized rain

Question 12

What types of clouds appear before a cold front comes through?

Answer 12

Cirrus and then cirrostratus

-these are high in altitude so as the clouds lower in altitude it means the cold front is approaching

Question 13

How are fronts identified on a map?

Answer 13

strong temperature differences on a map
humidity of air masses by looking at dew points; colder dew points have lower water vapor content

Question 14

Warm front

Answer 14

mass of warm air advances towards cold air

Question 15

What types of air masses usually in a warm front?

Answer 15

Maritime polar and maritime tropical

Question 16

What weather is associated with warm front?

Answer 16

typically associated with slow predictable changes, light precipitation for days, frontal fog (frontal fog usually at beginning of front)

Question 17

How is the slope of a warm front different from a cold front?

Answer 17

slope of a warm front is more gradual

Question 18

What types of clouds associated with warm fronts?

Answer 18

stratus clouds which are associated with horizontally elongated clouds

Question 19

Warm front cloud formation order

Answer 19

cirrus – cirrostratus – altostratus – nimbostratus – stratus

Question 20

How does a warm front appear on a radar map?

Answer 20

Produce a very large and wide area of cloud cover

Question 21

Stationary fronts

Answer 21

fronts that do not move or move very slowly
-there is motion along the front but there is no advancing of one air mass overtaking the other

Question 22

What types of air masses associated with stationary fronts?

Answer 22

Polar air mass from tropical air mass

Question 23

Occluded front

Answer 23

because the warm front is slower than the cold front, the cold front catches up to the warm front and displaces that warm air aloft

-warm is lifted due to density differences

Question 24

Cold Type Occlusion: where does it appear and what type of air?

Answer 24

-usually occurs in the eastern half of the continent
-continental polar air meets maritime tropical air

Question 25

Warm Type Occlusion: where does it appear and what type of air?

Answer 25

-usually occurs in western edges of continent
-maritime polar air coming in from the Pacific ocean catches up to continental polar

Question 26

Drylines

Answer 26

boundaries between humid and dry air without large temperature differences

Question 27

What type of air masses usually involved in drylines?

Answer 27

continental tropical air and maritime tropical air

Question 28

What weather is associated with drylines?

Answer 28

thunderstorm development and tornado outbreaks

Question 29

What does a dryline appear as on a map?

Answer 29

a black line with unfilled circles
temperature won’t be highly variable but dew point will be

Question 30

What phenomena explains why dry air is more dense than humid air at the same pressure and temperature?

Answer 30

Avogadro’s Law: explains that an equal volume of gas at the same temperature and pressure have the same number of molecules
-but water vapor molecules have less mass, so dry air is more dense than moist air (this causes moist air in drylines to be lifted, thus leading to storms)

Question 31

When and where are drylines most common?

Answer 31

common in Spring and Summer in Texas and the Southern Great Plains

Question 32

What determines the type of occlusion?

Answer 32

Stability differences between air masses

Question 33

How can occlusions arise?

Answer 33

1. When the circular core of low pressure changes shape and stretches
2. When the intersection of the cold and warm front slides along the warm front

Question 34

Where do cold and warm fronts meet

Answer 34

At the center of low pressure

Question 35

Why does the upper portion of a cold and warm fronts advance more rapidly?

Answer 35

wind speeds are higher at greater altitudes