ATC Basics: Current Weather - Clouds

What is the state of the sky in terms of sky cover, layers, and associated heights, ceiling, and cloud?

Sky condition

What is the amount of sky which is covered by clouds or obscurations in contact with the surface?

Sky cover

What is an array of clouds and/or obscurations whose bases are at approximately the same level?

Layer

What is a categorization of the amount of sky cover at and below each reported layer?

Summation layer amount

What is the lowest layer aloft reported as broken or overcast or the vertical visibility into an indefinite ceiling?

Ceiling

What is a subjective or instrumental evaluation of the vertical distance into a surface-based obscuration that an observer would be able to see?

Vertical visibility

What is the ceiling classification applied when the reported ceiling value represents the vertical visibility upward into a surface-based obscuration?

Indefinite ceiling

What is the contraction for vertical visibility?

VV

How much summation does vertical visibility cover?

8/8

What is the abbreviation for clear skies?

SKC or CLR

When is CLR used?

Automated stations (clear at/below 12,000)

When is SKC used?

Manual stations (no layers are reported)

How much summation does SKC/CLR cover?

0/8

What is the abbreviation for few clouds?

FEW

How much summation does few cover?

1/8-2/8

What is the abbreviation for scattered?

SCT

How much summation does SCT cover?

3/8-4/8

What is the abbreviation for broken?

BKN

How much summation does BKN cover?

5/8-7/8

What is the abbreviation for overcast?

OVC

How much summation does OVC cover?

8/8

Define the following abbreviations:

1. SKC

2. CLR

3. VV

4. BKN

5. OVC

6. SCT

7. FEW

1. Clear at manual station

2. Clear at automated station

3. Vertical visibility

4. Broken

5. Overcast

6. Scattered

7. Few

If there’s a cloud layer amount that’s greater than 0 but less than 1/8, how is it reported?

Few

What are the 3 options for sky conditions?

1. Cloud cover

2. Vertical visibility

3. Clear skies

What do the first three letters represent in the cloud cover section?

The amount of sky cover

What are the 4 options for sky cover that will be in the first 3 letters of the cloud cover section?

1. FEW

2. SCT

3. BKN

4. OVC

What do the 3 digits represent that come after the amount of sky cover in the cloud cover section?

Height of the layer

What is the unit of measurement for cloud cover?

Hundreds of feet

If cloud cover shows 000, what does that indicate?

Layer is 50 feet or less AGL

What does /// indicate in cloud cover?

Layer is below station level

What is the code for towering cumulus?

TCU

What is the code for cumulonimbus?

CB

How are TCU or CB clouds represented in the cloud cover section?

Appending their contraction to the layer that represents their base

In what order is sky condition coded?

Ascending

How is each layer of cloud cover reported?

Separated from other layers by a space

When a portion of the sky is obscured by a surface-based obscuration, how is the obscuration reported? (2 things)

1. Appropriate sky cover contraction

2. 000 entered for layer height

If a METAR says VV 005, how do you report that?

Indefinite ceiling at 500 (fog covers everything)

If you see BKN000 without any comments, how is it reported?

Sky partially obscured

If you see BKN000 with comments, how is that reported?

Ceiling less than five zero broken

If you see FEW000 without any comments, how would you report that?

Sky partially obscured

If you see FEW000 with comments, how would that be reported?

Few clouds at less than five zero

If you see SCT000 with comments, how would that be reported?

Less than five zero obscured

If you see SCT000 without comments, how would that be reported?

Sky partially obscured

If you see VV, how is that reported?

Indefinite ceiling

If you see SKC, how is that reported?

Sky clear

If you see CLR, how is that reported?

Clear below one two thousand

If you see FEW, how is that reported?

Clear below two thousand

When you see FEW, how is that reported?

Few clouds at (height)

If you see SCT, how is that reported?

(Height) scattered

If you see BKN, how is that reported?

Ceiling (height) broken

If you see OVC, how is that reported?

Ceiling (height) overcast