Thunderstorms Part 2(oxford)

Question 1

Frontal thunderstorms are:

• most frequent in _____.
• formed over land or sea, day or night.
• usually formed in a line at a ___ front or _______.
• found in active ________ or ____.
• often accompanied by a line ____.
• the _____ moving.

Answer 1

• most frequent in winter.
• formed over land or sea, day or night.
• usually formed in a line at a cold front or occlusion.
• found in active depressions or troughs.
• often accompanied by a line squall.
• the fastest moving.

Question 2

Hail can be met at any height in the cloud, also below the cloud and below the anvil.
Severe skin damage to the airframe can occur when the hail is large. Damaging hail can
occur up to a height of __000 feet.

Answer 2

45 000ft

Question 3

Microbursts can move downwards in excess of -

And up to -

The horizontal speed -

The wind shear can be between -

Answer 3

1 000ft/min

6 000ft/min

50kts

50 and 90kts

Question 4

Microbursts.

Are concentrated in a burst which is up to _ km in horizontal length and have a lifetime
of less than _37 minutes. (A macroburst is a similar event but over a bigger area.)
Microbursts are most likely to occur in summer air mass thunderstorms in low latitude regions
where surface conditions are dry. They cause extreme turbulence and severe windshear
conditions.
A warning sign is virga, which is streaks of precipitation from below the cloud which do not
reach the ground.

Answer 4

They are concentrated in a burst which is up to 4 km in horizontal length and have a lifetime
of less than 5 minutes. (A macroburst is a similar event but over a bigger area.)
Microbursts are most likely to occur in summer air mass thunderstorms in low latitude regions
where surface conditions are dry. They cause extreme turbulence and severe windshear
conditions.
A warning sign is virga, which is streaks of precipitation from below the cloud which do not
reach the ground.