Fronts Part 2(oxford)

Question 1

Air masses are identified by temperature/latitude, these include:

and by humidity or sea/land source:

Answer 1

• Equatorial.
• Tropical.
• Polar.
• Arctic.
• Equatorial.
• Tropical.
• Polar.
• Arctic.

Question 2

Air masses:

Arctic Maritime :

1. Source
2. Stability
3. Temperature
4. Moisture
5. Time of the year
6. Weather

Answer 2

1. Polar ice cap
2. Stable
3. Very cold
4. Dry
5. September and May
6. Humidity increase as it moves over the Norwegian sea, becoming very unstable. Large CU and CB.

Question 3

Air masses:

Polar Maritime:

1. Source
2. Stability
3. Temperature
4. Moisture
5. Time of the year
6. Weather

Answer 3

1. Northwest, North Atlantic
2. Stable
3. Cold
4. Absolute humidity low, relative humidity high
5. -
6. Approaching inland becomes unstable with CU and CB

Question 4

Air masses:

Polar Continental :

1. Source
2. Stability
3. Temperature
4. Moisture
5. Time of the year
6. Weather

Answer 4

1. Siberia
2. Stable
3. Cold
4. Dry
5. -
6. If from the east travelling over continental Europe, then very cold, very dry, no
   cloud, no precipitation. If the airflow comes over the Baltic or North Seas the air will become unstable, with large
   Cu and heavy snow showers on the E coast of Sweden and the UK. Remains very cold. In summer the air mass virtually disappears. However, with high pressure over Scandinavia in early to mid summer, there will be a NE flow over the North Sea to E UK. The air originates as dry, warm and stable. Over the North Sea it becomes moist and cool. This results in Haar conditions over E coast of N England and Scotland - very low St, drizzle, advection fog, poor visibility.

Question 5

Air masses:

Tropical Continental:

1. Source
2. Stability
3. Temperature
4. Moisture
5. Time of the year
6. Weather

Answer 5

1. N Africa/SE Europe.
2. Stable
3. Warm
4. Dry
5. Summer
6. No cloud or precipitation, warm or very warm. Visibility
   moderate except in dust haze which can occur.

Question 6

Air masses:

Tropical Maritime:

1. Source
2. Stability
3. Temperature
4. Moisture
5. Time of the year
6. Weather

Answer 6

1. The Azores anticyclone
2. Stable
3. warm
4. RH high, AH high.
5. -
6. Low cloud, St and Sc. Drizzle or light precipitation. Visibility poor. Advection fog over sea area late spring, early summer, over land winter, early spring. In high summer insolation and convection break down the stability resulting in clear skies or possibly a few small Cu

Question 7

The main global fronts are:

Fronts in a locality are named

Answer 7

• The Polar Front.
• The Arctic Front.
• The Mediterranean Front.
• The Intertropical Convergence Zone (ITCZ).

• Cold or warm

Question 8

Frontal surfaces which are in equilibrium with no tendency for
the cold air to undercut the warm, thus not convergence, is called -

Answer 8

quasi-stationary front

Question 9

If warm air is replacing cold air, then the front is called -

Answer 9

Warm front

Question 9

A warm front has an approximate slope of -

The slope of a cold front is approximately -

Answer 9

1: 150
1: 50 to 1:80

Question 10

If cold air is replacing warm air, then the front is called a -

Answer 10

cold front

Question 11

Clouds associated with a warm front -

Answer 11

CI, CS, AS, NS and SC.

Question 12

Clouds associated with a cold front -

Answer 12

CU, CB and AC

Question 13

The area lying between the two fronts is known as -

The type of weather -

Answer 13

The warm sector

Stratus and stratocumulus

Question 14

Ahead of a warm front:

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

Answer 14

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 15

At the warm front:

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

Answer 15

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 15

Warm sector:

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

Answer 15

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 16

At the cold front:

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

Answer 16

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 17

Behind the cold front:

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

Answer 17

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 18

Wind characteristics with fronts:

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 18

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