Microlight Training - Met - Clouds

Question 1

Stratus

Answer 1

Low Cloud
ST
Layer of sheet cloud. Varying Thickness.
Associated with rain or drizzle.
Sun can burn it off in the summer to reveal a good day.
Winter it persists all day and is referred to as Anticyclonic Gloom.
Fog is stratus whose base is at ground level.

Question 2

Nimbo-Stratus

Answer 2

Low Cloud
N ST
Dense sheet of amorphous shaped cloud.
Thickness can extend up to Medium cloud levels.
Associated with continuous rain preceding a warm front.

Question 3

Fracto-Nimbus

Answer 3

Low Cloud
F NIM
Air BELOW Nimbo-Stratus can become saturated by the rain passing through it.
Condenses into ragged fragments of cloud. - Referred to as SCUD CLOUD.

Question 4

Strato-Cumulus

Answer 4

Low Cloud
StCu
Patches of cloud, ‘lumpy’ in appearance with no great thickness or particular shape.
Not indicative of any type of weather.
Can produce light rain if thick enough when associated with diff types of front.

Question 5

Small Cumulus

Answer 5

Low Cloud
Cu
Small puffy cloud whose base is always flat and the top is rounded.
Length of the base is greater than the height.
Known as a ‘Fair Weather Cloud’

Question 6

Large Cumulus

Answer 6

Low Cloud
Cu
Heigh exceeds the width of the base.
Recognised as a towering cloud with cauliflower shaped tops.
As long as the tops are crisp in shape it is still active. Once ragged, then growth has stopped.
Large Cu produce showers which can be heavy or light depending on the size of the cloud.
Tops can extend up into medium cloud levels above.

Question 7

Cumulo-Nimbus

Answer 7

Low Cloud
Cb
These are Large Cumulus which have climbed into the high cloud levels and the tops have become ice crystals - known as FALSE CIRRUS.
Anvil shape.
Thunderstorms, hail, heavy rain, squalls - all products of a CuNimb.
Surface winds can alter in terms of direction and speed causing wind sheer.

Question 8

Mammatus

Answer 8

Low Cloud
Mamma
Forms under the anvil of a CuNimb or Alto-Cumulus.
They appear as ‘Inverted cumulus’ with an udder like shape.

Question 9

Alto-Cumulus

Answer 9

Medium Cloud
Ac
Is Starts-Cumulus at medium level. (Above 6000ft)
Forms a pattern referred to as Mackerel Sky.

Question 10

Alto-Cumulus Cumulus Genitus

Answer 10

Medium Cloud
AcCu-CuGen
Formed by large cumulus spreading out on reaching equilibrium.
Can cover a large area of sky - cutting out suns rays - reducing thermal activity.
Can develop into Mammatus.

Question 11

Alto-Stratus

Answer 11

Medium Cloud
A St
Stratus at medium heigh level.
If it’s lowering and thickening from the west, there is probably a warm front on the way bringing Nimbo-Stratus and rain.

Question 12

Alto-Cumulus Lenticularis

Answer 12

Medium Cloud 
Ac Lent
Clouds forms by standing waves in the lee of mountain ranges. 
Cigar shaped. 
They don't move across the sky.

Question 13

Alto-Cumulus Castellatus

Answer 13

Medium Cloud
Ac Cast
GR NOTE: CASTLE - Turret
A form of alto-cumulus usually appearing after a hot spell.
Hard turreted outline.
Warning of thundery conditions developing in a day or so.

Question 14

Cirrus

Answer 14

High Cloud
Ci
Composed of ice crystals due to height.
Mares Tails - streaks which turn up at the ends.

Question 15

Cirro-Stratus

Answer 15

High Cloud
Ci St
Stratus at high level.
If thickening and lowering into Alto-Stratus on the west, first sign of a warm front on the way.

Question 16

Cirro-Cumulus

Answer 16

High Cloud
Ci Cu
Formed of ice crystals. 
Also forms the Mackerel Sky pattern. 
Associated with quiet weather.