4. Air Masses and Fronts

Question 1

Air mass characteristics

Answer 1

Large volume of air, uniform in temp and moisture.

Question 2

Continental arctic

Answer 2

Dry, very cold, very stable, very low tropopause

Question 3

Maritime arctic

Answer 3

Moist, cold, unstable in lower levels, low tropopause

Question 4

Continental polar

Answer 4

Dry, cold, fairly stable, low tropopause

Question 5

Maritime polar

Answer 5

Moist, warm, unstable, medium tropopause

Question 6

Continental tropical

Answer 6

Dry, very hot, very unstable, very high tropopause

Question 7

Maritime tropical

Answer 7

Very moist, hot, very unstable, high tropopause

Question 8

How are air masses modified?

Answer 8

1. Speed that they move
2. Moisture/dryness of the region they travel over
3. Temp difference between the new surface and the air mass

Question 9

Warming from below

Answer 9

Develops instability and convection in lower levels

Question 10

Cooling from below

Answer 10

Causes increased stability in the lower levels

Question 11

Frontal system definition

Answer 11

Transition zones between air masses where the temp changes rapidly

Question 12

Naming of frontal systems

Answer 12

Based on the name of the colder air mass involved

Question 13

Cold front winds (before, while, and after passing)

Answer 13

Southeast-southwest, gusty and shifting, southwest-northwest

Question 14

Cold front temp (before, while, and after passing)

Answer 14

Warm, sudden drop, steadily dropping

Question 15

Cold front pressure (before, while, and after passing)

Answer 15

Falling steadily, minimum then sharp rise, rising steadily

Question 16

Cold front clouds (before, while, and after passing)

Answer 16

Cirrus then cirrostratus then cumulonimbus, cumulonimbus, cumulus

Question 17

Cold front precipitation (before, while, and after passing)

Answer 17

Short period of showers, heavy rain/sometimes hail/ thunder and lighting, showers then clearing

Question 18

Cold front vis (before, while, and after passing)

Answer 18

Fair to poor in haze, poor followed by improving, good except in showers

Question 19

Cold front humidity (before, while, and after passing)

Answer 19

High remains steady, sharp drop, lowering

Question 20

Warm front winds (before, while, and after passing)

Answer 20

Southeast-southwest, variable, southwest-southwest

Question 21

Warm front temp (before, while, and after passing)

Answer 21

Cool-cold, steady rise, warmer then steady

Question 22

Warm front pressure (before, while, and after passing)

Answer 22

Usually falling, levelling off, slight rise then fall

Question 23

Warm front clouds (before, while, and after passing)

Answer 23

Cirrus/Cirrostratus/Altostratus/Nimbostratus/Stratus/Fog, nimbostratus or stratus, clearing/scattered stratocumulus

Question 24

Warm front precipitation (before, while, and after passing)

Answer 24

Light/moderate/heavy, drizzle or none, usually none

Question 25

Warm front vis (before, while, and after passing)

Answer 25

Poor, poor but improving, fair in haze

Question 26

Warm front humidity (before, while, and after passing)

Answer 26

Steady rise, steady, rise then steady

Question 27

Frontal wave

Answer 27

Where cold and warm fronts join (usually a low in this position)