Low Pressure System

Question 1

In the NH, which way does win flow in a low pressure system

Answer 1

ANTI CLOCKWISE

Question 2

In a low pressure system, air is usually STABLE or UNSTABLE

Answer 2

UNSTABLE

Question 3

Which front moves faster, COLD or WARM

Answer 3

COLD

Question 4

When warm air pushes into cold air, this is known as what

Answer 4

WARM FRONT

Question 5

When cold air pushes into warmer air, this is known as what

Answer 5

COLD FRONT

Question 6

What is an occluded front

Answer 6

Where cold and warm air fronts join together

Question 7

What are the 2 types of occluded fronts

Answer 7

1. COLD
2. WARM

Question 8

What is the definition of a cold occlusion

Answer 8

Cold Air catches up to cool air

Cold air may not be as cold as the front ahead of it

Question 9

What is the definition of a warm occlusion

Answer 9

Cool air catches up to cold air

Question 10

What are the areas between fronts known as

Answer 10

SECTORS

Question 11

Describe the key characteristics of a warm sector

Answer 11

1. Area of warmer air behind a warm front
2. Between warm and cold fronts
3. In a depression

Question 12

Describe the key characteristics of a cold sector

Answer 12

1. Area of colder air immediately behind a cold front
2. Between cold and warm fronts
3. In a depression

Question 13

Describe the key characteristics of a cool sector

Answer 13

1. Area immediately ahead of a warm front
2. Caused by mixing of warm and cold air
3. Cold air comes from the cold front ahead of the warm front

Question 14

What are the 3 sectors of fronts
What order are they typically in

Answer 14

1. Warm Sector
2. Cool Sector
3. Cold Sector

Warm Sector –> Behind cool sector –> Behind Cold Sector –> Behind a warm sector

Review here

Question 15

What is the slope ratio if a warm front

Answer 15

1:150

Question 16

What is the typical spread (distance) of a warm front

Answer 16

500nm

Question 17

How is a warm front formed

Answer 17

Warm air rises up colder air

Question 18

Why do warm fronts typically form clouds

Answer 18

As air rises it cools
Relative himidty increases
Condensation occurs

Question 19

what are 4 characteristics of the passing of a warm front;
1. Wind
2. Pressure
3. Temperature and dew point
4. Rain

Answer 19

1. Surface wind veers
2. Pressure steadies then decreases
3. Temperature and dew point increase
4. Precipitation decreases

Question 20

What happens to warm air as the cold front approaches

Answer 20

1. Forced to Rise
2. Cools and condenses

Question 21

What type of rain fall can be expected with a cold front
Over what time frame

Answer 21

1. Sharp showers
2. Heavy rainfall
3. Short period of time

Question 22

What cloud type might be present 500nm ahead of a cold front

Answer 22

CIRRUS

CI

Question 23

What cloud type might be present 200nm ahead of a cold front

Answer 23

Cumulus

CU

Question 24

Wind VEERS or BACKS with the passing of a front

Answer 24

VEERS

Question 25

What are 5 characteristics of the passing of a cold front;
1. Surface wind
2. Pressure
3. Temperature and dew point
4. Cloud
5. Weather and visibility

Answer 25

1. Surface wind veers sharply (Gusting)
2. Pressure low, then sudden increase
3. Temperature and Dew point drop sharply
4. Patchy low cloud behind front
5. Abrupt weather change to fine and good visibility

Question 26

Warm fronts travel at what speeds compared to cold fronts

Answer 26

2/3 the speed

Question 27

Occluded front 2 characteristics

Answer 27

1. Air touching ground associated with “cold” sector
2. End of depression

Question 28

What is a trough of low pressure

Answer 28

CONCENTRATED LOW PRESSURE

Squeezed between two high pressure systems
Close isobars
Severe weather, increased mixing & lifting

Question 29

A danger of squall lines to a pilot

Answer 29

No easy way around them