Forecasts and reports
Significant abbreviations AIP GEN 3.5
In reports, forecasts and graphical area forecasts (GAFs), the amount of cloud is indicated by the following abbreviations:
SKC |
Sky clear |
|
FEW |
Few |
1 to 2 OKTAS (OKTAS refers to the fraction of the sky covered by cloud expressed in eighths) |
SCT |
Scattered |
3 to 4 OKTAS |
BKN |
Broken |
5 to 7 OKTAS |
OVC |
Overcast |
8 OKTAS |
NSC and CAVOK |
Nil significant cloud |
The only cloud types that are included in aeronautical code format are towering cumulus (TCU) and cumulonimbus (CB). Forecasts, such as graphical area forecasts (GAFs), will also include cloud types other than CB and TCU when appropriate; and in the case of CB cloud, the amount will be indicated in ‘non-aerodrome’ type forecasts as follows:
ISOL |
Isolated |
For individual CBs |
OCNL |
Occasional |
For well-separated CBs |
FRQ |
Frequent |
For CBs with little or no separation |
>10KM is used in the visibility section of graphical area forecasts (GAFs) to indicate a visibility greater than 10 km over the entire area. When weather elements are forecast to reduce the visibility below 10 km, the weather and associated visibilities are given. Note that the visibility remains greater than or equal to 10 km in parts of the area unaffected by those elements (AIP GEN 3.5).
Weather code and translation (AIP GEN 3.5)
Weather descriptors |
|
BC |
Patches (or patches of) |
BL |
Blowing |
DR |
Drifting |
FZ |
Freezing |
MI |
Shallow |
SH |
Showers (or showers of) |
TS |
Thunderstorms (or thunderstorms with) |
PR |
Aerodrome partially covered (used only to describe FG) |
Phenomena |
|
BR |
Mist |
DU |
Dust |
DS |
Dust storm |
DZ |
Drizzle |
FC |
Funnel clouds |
FG |
Fog |
FU |
Smoke |
GR |
Hail |
GS |
Small hail pellets |
HZ |
Haze |
PL |
Ice pellets |
PO |
Dust devils |
RA |
Rain |
SA |
Sand |
SG |
Snow grains |
SN |
Snow |
SQ |
Squalls |
SS |
Sand storm |
UP |
Unknown precipitation (from weather sensor) |
VA |
Volcanic ash |
Notes
- Intensity is indicated with precipitation, duststorms and sandstorms. In these cases, the weather code is prefixed by the qualifier ‘-‘ for light, or ‘+’ for heavy. Moderate intensity is indicated by the absence of a prefix.
- METAR/SPECI may provide an indication of weather in the vicinity (within approximately 8–16 km of the aerodrome reference point). The proximity qualifier ‘VC’ will be used only in combination with the abbreviations: TS, DS, SS, FG, FC, SH, PO, BLDU, BLSA and BLSN.