Cloud Flashcards
Name the 4 types of low cloud
- Cumulus
- Stratocumulus
- Stratus
- Nimbostratus
Name the 2 types of medium level cloud
- Altocumulus
* Altostratus
Name the 5 types of high level cloud
- Cirrocumulus
- Cirrus
- Cirrostratus
- Cumulonimbus
- Towering Cumulus
Which type of cloud is associated with moderate or heavy rain?
Nimbostratus
Name the only 2 cloud types that are reported in the metar
- Towering Cumulus (TCU)
* Cumulonimbus (CB)
Which type of cloud is ‘Cauliflower-Shaped’?
Towering Cumulus
Which type of cloud is anvil shaped?
Cumulonimbus
If reporting thunderstorms (TS), do clouds have to be present in the METAR?
Yes, one of either TCU or CB must be reported in the METAR when reporting TS.
How are TCU or CB clouds reported?
They are reported after cloud amount and height as ‘TCU’ or ‘CB’
What is the automated cloud sensor called?
Ceilometer
What are the definitions of FEW, SCT, BKN and OVC?
They relate to the amount of sky, divided into oktas (8ths), covered by cloud.
• FEW - No more than 1/4 (1-2 oktas)
• SCT - Scattered - Between 1/4 and 1/2 (2-4 oktas)
• BKN - Broken - Over 1/2 but not full (5-7 oktas)
• OVC - Overcast - Complete cloud cover (8 oktas)
How is cloud height reported, and what are the cloud rounding rules?
Cloud is reported in AGL, in 100’s of feet, rounded down to the nearest 100ft.
What is the maximum height cloud that can be reported
4900ft (049). Cloud with a base of 5000ft or higher is not reported, unless it is TCU or CB.
How does speed of clouds relate to its height?
Often, the faster the cloud is moving, the lower the cloud height.
How is a cloud height of less than 100ft reported?
‘000’
Are TCU and CB’s reported if their height is above 5000ft?
Yes. TCU and CB’s must be reported even if their height is above 5000ft.
In what order are clouds reported?
They are reported in base height order, from lowest cloud to highest cloud, following the layer rules.
How many cloud layers can be reported and what are the rules?
A maximum of 4 layers can be reported, subject to the following rules:
1st Layer : Report the lowest layer, whatever the amount.
2nd Layer : Only to be reported if the amount is 3 oktas or more (SCT, BKN, OVC)
3rd Layer : Only to be reported if the amount is 5 oktas or more (BKN, OVC)
4th Layer : Only to be reported as TCU or CB if omitted by the above rules.
What is to be reported if CB and TCU cloud masses have a common base?
Report the sum of the amounts as CB.
What is NCD?
No cloud discernible and it is only to be used by automated systems.
