Chapter 12: Cloud Classification (PP ch 12)

Question 1

WMO
Cloud levels (3)

Answer 1

World Meteorological Organisation

Polar: 0 - 65 (low) ; 65 - 130 (middle) ; 100 - 250 (high)
Temp: 0 - 65 (low) ; 65 - 230 (middle) ; 165 - 450 (high)
Trop: 0 - 65 (low) ; 65 - 250 (middle) ; 200 - 600 (high)

Question 2

Cloud Coverage
Ceilometer
Cloud top

Answer 2

0 oktas: SKC
1 - 2: FEW
3 - 4: SCT (Scattered)
5 - 7: BKN (Broken)
8: OVC (Overcast)

Ceilometer - laser measures cloud base
Cloud top measured with satellite / triangulation

Question 3

High Clouds (3)

Answer 3

(Ci) Cirrus - ice crystals, filamenty
(Cc) Cirrocumulus - cotony, round
(Cs) Cirrostratus - halo effect

Question 4

Medium Clouds (2)

Answer 4

(As) Altostratus - SCWD, water

(Ac) Altocumulus - SCWD, cotony, round

Question 5

Low Clouds (4)

Answer 5

(St) Stratus - poor vis
(Cu) Cumulus - fluffy, isolated, blue sky
(Sc) Stratocumulus
(Ns) Nimbostratus - dark, grey, rain

Question 6

Cumulus Family (7)

Answer 6

Cu Humilis (Cu hum) - fair weather cumulus < FL100
Cu Mediocris (Cu med) - flat base < FL100, med extent
Cu Congestus (TCu) - < FL250
Cb Calvus (Cb calv) - sharp outline < FL450
Cb Capillatus (Cb cap) - hair-like at top, ice crystals
Cb Incus
Cb - Cumulonimbus

Question 7

Other Clouds (3)
Adjective for broken up clouds

Answer 7

(Acc) Altocumulus castellanus - castle-like
Mammatus - cumuliform protuberance in TS cloud
Lenticularis - orographical cloud

Fractus - broken up clouds

Question 8

Sigwx

ISOL - OCNL - FRQ - EMBD - WDSPD

Answer 8

Isolated
Occasional
Frequent
Embedded
Widespread