Chapter 18 - Fronts and Frontal Depressions

Question 1

Weather fronts is…?

Answer 1

A boundary separating two masses of air of different temperature and/or density

Question 2

What is the reason for using the term “zone” to describe a frontal zone where the transition from one mass to another is gradual, and how wide can this boundary be?

Answer 2

The boundary can be diffuse, even a few kilometres wide, hence the term zone to describe a fontal zone where a change from one mass to the other is gradual

Question 3

How are fronts represented in surface weather analyses, and what determines the choice of colors, triangles, and half-circles used to depict them based on the type of front?

Answer 3

In surface weather analyses, fronts are depicted using various coloured triangles and half-circles, depending on the type of front

Question 4

What is the main global frontal systems?

Answer 4

Polar fronts, the artic front and the equatorial trough/ITCZ

Question 5

Warm front is…?

Answer 5

The leading edge of an advancing mass of warm air that rises over and replaces a retreating mass of cooler air

Question 6

Winter Warm fronts tend to produce more or less weather?

Answer 6

More

Question 7

What are the warm front slopes forward relative to?

Answer 7

Relative to its movement with the slope of 1:150

Question 8

What are the conditions at a warm front?

Answer 8

• Cloud: Ci, Cs, As, Ns/St. (sequence leading towards the surface position of the warm front)
• Weather: Steadily worsening to intermittent/continous rain/drizzle/snow at the front
• Ground visibility: Decreasing towards the front; working at the front
• Wind: Backs initially then veers at the passing of the front
• Aviation hazards: Potential FZRA/fZDZ, moderate rime icing, low cloud, poor visibility; possible mist and fog

Question 9

Cold front is…?

Answer 9

The leading edge of an advancing mass of cold air which is replacing a warmer air mass at the surface

Question 10

Winter cold fronts tend to produce more or less weather?

Answer 10

More

Question 11

What are the cold front slope backwards relative to?

Answer 11

its movement with a slope approx. 1:75

Question 12

cold front at the surface has small or big forward sloping section?

Answer 12

small

Question 13

Conditions for cold fronts

Answer 13

• Cloud: Embedded Cu/CB in Ns and St, then As Ac. Cs Cc and the finally Ci well behind the front
• Ground visibility:
  -Pressure:
• Aviation hazards: