Figure 1-13. Sky Coverage

METEOROLOGY FLIGHT PLANNING

CHAPTER ONE

Group 8: Sky Condition

METAR KNPA 082255Z 27004KT 7/8SM R04/4500FT DZ FG SCT000 BKN011 OVC380

19/18 A2997 RMK VIS1/2V1 CIG009V013 FG SCT000 BKN TOPS 027

SLP149

Figure 1-12 Sky Condition in METAR

The sky condition group (Figure 1-12) gives a description of the appearance of the sky including

the type of clouds, cloud layers, amount of sky coverage, height of their bases, and any

obscuring phenomena. Cloud layer amounts for each layer indicate eighths of the sky that is

covered, according to the abbreviations in Figure 1-13.

Reportable

Amount of

Meaning

Contractions

Sky Cover

SKC or CLR1

Sky Clear

0/8

Few

> 0/8 - 2/8

FEW

SCT

Scattered

3/8 - 4/8

BKN

Broken

5/8 - 7/8

OVC

Overcast

8/8

8/8 (surface based)

Obscured

1. The abbreviation CLR is used at automated stations when no clouds at or below 12,000 feet

are reported; the abbreviation SKC is used at manual stations when no clouds are reported.

2. Any amount less than 1/8 is reported as FEW.

3. The last 3 digits report the height of the vertical visibility into an indefinite ceiling.

Figure 1-13 Sky Coverage

In addition to the notes of Figure 1-13, the following are some of the cloud reporting rules used

in METAR/SPECI.

All sky cover heights are reported in feet above the ground level (AGL).

Sky condition is annotated by a six-digit group, the first three digits (letters) describing the

amount of sky cover (from figure 1-13), and the second three digits (numbers) the height of that

layer in hundreds of feet. Layers will be reported in ascending order up to the first overcast. If

the cloud layer is below the station (for mountain stations), the height will be coded as ///.

3. When the sky is totally obscured by a surface-based obscuration the only group in the sky

condition section will be a five-digit group, the first two digits VV (Vertical Visibility) and the

last three digits the height of the vertical visibility into the indefinite ceiling. Most always this

height will be 000, as any surface-based phenomenon is (by definition of "surface-based") within

50 feet of the surface, and will be rounded down to the nearest hundred feet (i.e., zero).

AVIATION ROUTINE WEATHER REPORTS AND TERMINAL AERODROME

FORECASTS 1-11