Lesson 108

Question 1

Define front

Answer 1

The transition zone between two air masses

Question 2

Define frontal surface

Answer 2

The transition zone separating the warm and cold air aloft.

Question 3

Define surface front

Answer 3

The transition zone separating the warm and cold air touching the earth’s surface.

Question 4

Fronts are generally always associated with areas of _________ pressure and in particular _________________ pressure.

Answer 4

Low

Troughs of low

Question 5

At a warm front, the factors that determine the type of cloud and precipitation are:
The _____________ content of the overrunning warm air
The _____________ of the overrunning warm air
The _____________ of overrunning

Answer 5

Moisture
Stability
Degree

Question 6

At a cold front, the factors that determine the type of cloud and precipitation are:
The ________ content of the lifted warm air.
The ________ of the lifted warm air.
The ________ of lift (the slope of the frontal surface and sped of the front).

Answer 6

Moisture
Stability
Degree

Question 7

Whatever direction an aircraft flies from, when crossing a frontal surface the aircraft will have to correct its heading to the _______.

Answer 7

Right

Question 8

If a moist and stable warm front is approaching your station, expect ________ clouds in what order? And ___________ precipitation.

Answer 8

Layer
CI, CS, AS, NS

Continuous (SF and frontal fog forming in the precip)

Question 9

If the warm air is moist and unstable, expect the same clouds as the moist and stable air mass with the addition of ___________ embedded in the layer cloud.

Answer 9

Cumulonimbus

Question 10

At a cold front, if the warm air is moist and stable and:
If advancing slowly, expect wide spread ____________ clouds, and ________ or _________ precipitation.
- if advancing rapidly, then expect a _________ band of _______ clouds, and _______ or _________ precipitation.

Answer 10

Layer, intermittent or continuous

Narrow, layer, intermittent or continuous

Question 11

At a cold front, if the warm air is moist and unstable, expect _____________ and __________ precipitation

Answer 11

Heap (cumuliform) cloud

Showery

Question 12

If an aircraft encounters occasional heavy precipitation while flying in the colder air beneath a frontal surface, this would indicate.

Answer 12

Thunderstorms are present in the warm air aloft

Question 13

What types of precipitation would a pilot encounter when flying toward a warm front at low levels? At higher levels?

Answer 13

Snow, snow and ice pellets mixed, ice pellets and freezing rain mixed and then freezing rain.

The same as above but no ice pellets.

Question 14

If the temperature difference across the front at the surface is ________ or more, and the front is moving at a speed of __________, then wind shear and its associated turbulence is likely to be present.

Answer 14

5 degrees C

30 Kt or more

Question 15

A frontal wave is formed by a ____________ forming at some point on a front.

Answer 15

Low

Question 16

Define frontal wave.

A wave-shaped distortion an a front usually associated with a ____________.

Answer 16

Trough

Question 17

The area situated between the cold front and the warm front to the east is called the _________________.

Answer 17

Warm sector