METEOROLOGY FLIGHT PLANNING
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
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.
SKC or CLR1
> 0/8 - 2/8
3/8 - 4/8
5/8 - 7/8
8/8 (surface based)
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
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