Mnemonics and Main Memory Items | MET | Air masses and Fronts

Question 1

Wind characteristics with fronts NH:

1. Ahead of the warm front -
2. At the warm front -
3. Warm sector(between the cold and warm front) -
4. At the cold front -
5. Behind the cold front -

Answer 1

1. Steady increasing, slightly backing, usually southerly.
2. Sharp veer
3. Steady, usually from SW
4. Sharp veer, gusts and squalls likely due to CB
5. Steady or slight veer

Question 2

Behind the cold front NH:

Surface W/V - 
Temperature - 
Dew Point - 
Pressure - 
Cloud - 
Precipitation -
Visibility

Answer 2

Surface W/V - Steady or slight veer to NW.
Temperature - Steady low.
Dew Point - Steady low.
Pressure - Rises slowly.
Cloud - 6/8, base lifting, Cu, Cb.
Precipitation - Showers, heavy at times, hail and TS possible.
Visibility - Very good, except in showers.

Question 3

At the cold front NH:

NH

Surface W/V - 
Temperature - 
Dew Point - 
Pressure - 
Cloud - 
Precipitation - 
Visibility -

Answer 3

Surface W/V - Sharp veer, gusts and squalls likely.
Temperature - Sudden fall.
Dew Point - Sudden fall.
Pressure - Starts to rise.
Cloud - 6/8 to 8/8, base low but rising, Cu, CB, sometimes Ns.
Precipitation - Heavy rain or snow showers, thunder and hail possible.
Visibility - Good, except in precipitation.

Question 4

Warm sector NH:

Surface W/V - 
Temperature - 
Dew Point - 
Pressure - 
Cloud - 
Precipitation - 
Visibility -

Answer 4

Surface W/V - Steady, usually from the SW.
Temperature - Steady.
Dew Point - Steady.
Pressure - Slight fall.
Cloud - 6/8 to 8/8, some large breaks may occur, base low, St, Sc.
Precipitation - Light rain, drizzle
Visibility - Poor, possibly advection fog in winter.

Question 5

At the warm front NH:

Surface W/V - 
Temperature - 
Dew Point - 
Pressure - 
Cloud -  
Precipitation -  
Visibility -

Answer 5

Surface W/V - Sharp veer. 
Temperature - Sudden rise. 
Dew Point - Sudden rise. 
Pressure - Stops falling.
Cloud - 8/8, base very low, Ns, St. 
Precipitation - Moderate or heavy continuous. 
Visibility - Very poor, fog can occur

Question 6

Ahead of a warm front NH:

Surface W/V - 
Temperature - 
Dew Point - 
Pressure - 
Cloud - 
Precipitation - 
Visibility -

Answer 6

Surface W/V - Speed increasing, slight backing, usually southerly.
Temperature - Steady low.
Dew Point - Steady low.
Pressure - Steady fall.
Cloud - Increasing to 8/8, base lowering, Ci, Cs, As, Ns.
Precipitation - Light continuous from As becoming moderate to heavy continuous from Ns.
Visibility - Reducing to poor.

Question 7

The area lying between the two fronts is known as -

The type of weather -

Answer 7

The warm sector

Stratus and stratocumulus

Question 8

Clouds associated with a warm front -

Answer 8

CI, CS, AS, NS and SC.

Question 9

Clouds associated with a cold front -

Answer 9

CU, CB and AC

Question 10

The passage of a warm front can be associated with areas of fog. The types of fog just in advance and just after the passage are respectively

Answer 10

frontal fog and advection fog

Question 11

What will be the effect on the reading of an altimeter of an aircraft parked on the ground as an active cold front is passing?

Answer 11

It will first increase then decrease

A decrease in pressure will cause the altimeter to increase, and vice-versa

Question 12

Pressure characteristics of a cold front:

Approaching cold front -
At the cold front -
behind the cod front -

Answer 12

steady decreasing
steady Increasing
slowly rising

Question 13

In which approximate direction does the centre of a frontal depression move?

Answer 13

In the direction of the warm sector isobars

The depression tends to move in a direction parallel to the first two isobars in the warm sector.

Question 14

An occlusion has the characteristics of a warm front when

Answer 14

the cold air behind is warmer than the cold air ahead

Question 15

In a warm front occlusion:

Answer 15

the warm air is lifted

Question 16

How to tell whether it is a cold occlusion or warm occlusion on a chart?

Answer 16

The occlusion will follow the line of the air mass it is associated with. I.E

Warm front occlusion will follow the warm front line
Cold front occlusion will follow the cold front line

Question 17

Which occlusion:

X occurs when a fast moving cold front is colder than the air ahead of the slow moving warm front. When this occurs, the cold air replaces the cool air and forces the warm front aloft into the atmosphere. Typically, the cold front occlusion creates a mixture of weather found in both warm and cold fronts, providing the air is relatively stable.

Answer 17

A cold front occlusion

Question 18

Which occlusion:

X occurs when the air ahead of the warm front is colder than the air of the cold front. When this is the case, the cold front rides up and over the warm front. If the air forced aloft by the warm front occlusion is unstable, the weather is more severe than the weather found in a cold front occlusion. Embedded thunderstorms, rain, and fog are likely to occur.

Answer 18

A warm front occlusion

Question 19

Between a warm front occlusion and a cold front occlusion, which will provide the worst weather?

Answer 19

Warm front occlusion

Question 20

Mnemonic to remember occlusions:

Answer 20

Which ever pushes the other up, is the dominant front type.

If the cold air is pushed up, it is a warm front occlusion.

If the warm air is pushed up, it is a cold front occlusion.

Question 21

If shown a chart of the front cross section, and two lines that intersect is shown -

Answer 21

It’s an occlusion

Question 22

Which is true of a secondary depression in the northern hemisphere?

Answer 22

It tends to move round the primary in a cyclonic sense

Question 23

What is encountered during the summer, over land, in the centre of a cold air pool?

Answer 23

Showers and thunderstorms

Question 24

How do you recognize a cold air pool?

Answer 24

As a low pressure area aloft (e.g. On the 500 hPa chart)

Question 25

The region of the globe where the greatest number of tropical revolving storms occur is:

Answer 25

the north west Pacific, affecting Japan, Taiwan, Korea and the Chinese Coastline

Question 26

Thunderstorms in exceptional circumstances can occur in a warm front if:

Answer 26

the warm air is convectively unstable

Question 27

The boundary between polar and tropical air is known as:

Answer 27

Polar front

Question 28

The arctic front is the boundary between:

Answer 28

polar air and arctic air

Question 29

When do cold occlusions occur more frequently in Europe?

Answer 29

Summer

Question 30

The passage of a warm front can be associated with areas of fog. The types of fog just in advance and just after the passage are respectively

Answer 30

frontal fog and advection fog