Fronts

Question 1

Surface changes with the passage of a cold front:

1. Temperature -
2. Dew point -
3. Visibility -
4. Pressure -
5. Wind -

Answer 1

1. Marked and sudden drop as the cold air moves in to replace the warm air. After the passage it remains low, but steady.
2. Drop in dew point as cold air hold less water vapour.
3. This decreases with the approach of the front and is significantly reduced in the rain sector. A rapid improvement occurs after the passage, becoming excellent.
4. With the advance of the front, pressure falls steadily until at the passage a marked drop occurs suddenly. After the passage, it remains steady or begins to rise slowly.
5. A sharp backing of the wind

Question 2

Between a cold and a warm front, which has a steeper “slope”?

Answer 2

Cold front

Question 3

A warm front is a front that moves along when warm air is gently forced to ascend -

Answer 3

up and over cold air

Question 4

A cold front tis a front that moves along replacing -

Answer 4

warm air at the ground.

Question 5

Cold front weather:

The cloud that can be expected within, ahead and on the front line of a cold front -

Answer 5

For an unstable front:

Cumulus type behind the front line, cumulonimbus and nimbostratus on the front line. Ahead of the front line more cumulonimbus.
Also showers, icing, hail, turbulence and lighting.

For a stable front:

Cloud of the stratus type inside the front, altostratus and nimbostratus on the front line extending to ahead of the front. Precipitation will rain and not showers.

Question 6

Warm front weather:

The cloud that can be expected with a warm front(moist warm stable, warm moist unstable and warm dry stable) -

Answer 6

For a moist, warm and stable air front:

Stratiform type cloud with increasing precipitation as the front approaches. When flying towards the front from the cold air side in the following order -

Cirrus, Cirrostratus, altostratus and nimbostratus.

For a warm. moist unstable air front:

The approach of this front is the same as with the previous. But the front core will consist of altocumulus and embedded cumulonimbus which will raise the humidity of the cold air ahead of the front causing low ceilings of stratus, fog and poor visibility which is followed by heavy showers and possibly hail.

For a warm, dry stable air front:

High level clouds such as altocumulus, altostratus, cirrostratus and cirrus.

Question 7

Surface changes with the passage of a warm front:

1. Temperature -
2. Dew point -
3. Visibility -
4. Pressure -
5. Wind -

Answer 7

1. A steady rise at the advance and during the passage. After the passage, temperatures remain high and steady.
2. A rise in dew point due point during the advance, reaching a maximum after passage.
3. Fairly good with advance, reducing significantly with the precipitation area. After passage, remains poor to moderate with fog and mist.
4. Pressure will fall steadily during the approach and after the passage continue to fall at a slower rate until they steady out.
5. With the passage the strong winds will back.

Question 8

The type of front covering a wider area?

Answer 8

Warm front.

Question 9

The 5 five factors which determine weather intensity at any front type -

Answer 9

1. The slope of the front
2. Stability of the warm air mass
3. Moisture content of the warm air mass
4. The temperature difference between the two air masses
5. The speed of the overtaking air mass