Pre-Flight Planning resources

Pre-Flight Planning

Meteorology

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

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

IC

Ice crystals  (very small ice crystals in suspension, also known as diamond dust)

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

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