Attachment
Attachment
METAR Examples
TAF Examples
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METAR CODE FORMAT
CCCC Location or Place - Four letter ICAO ID's designators are is used. (see: Locations)
AUTO Used when the observation is done without any human intervention.
VnVnVnVnDv
When the horizontal visibility is not the same in all directions, and the minimum visibility is <
1500m, or < 50% of the prevailing visibility a minimum and maximum visibility may be given
followed by the direction.
Dv is reported as the operationally lowest significant direction as one of the eight
points of the compass (N, NE, etc.), and consists of one or two letters only.
Values for D are:
N - North, NE - Northeast, E - East, SE - Southeast, S - South,
SW - Southwest, W - West, NW - Northwest.
CAVOK.
Coded in place of the visibility, present weather and cloud groups when the following conditions
occur simultaneously at the time of observation:
RDRDR/ - Runway designator/point where the visibility is measured, coded as two digits.
VRVRVRVR - Measured visibility in meters.
i - Indicator for tendency in change in visibility
U – upward
D – downward
N - no tendency
RDRDR/VRVRVRVRvVRVRVRVRi Runway Visual Range when variation in visibility has been observed.
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The fluctuation is considered significant when the visibility during the last 5 seconds
changes by 50m or 20% of the mean visibility of the previous 10 minutes.
v - Tendency for the visibility to change by 100m or more from the mean.
ww Weather
Used to report significant weather. The table below shows the abbreviations.
NsNsNshshshs Clouds (see also: CAVOK, NSC, Cloud Type, Cloud Atlas)
NsNsNs Cloud amount
The following abbreviations are used:
FEW - 1 to 2 octas
SCT - 3 to 4 octas
BKN - 5 to 7 octas
OVC - 8 octas
TT/TdTd Temperatures
TT – Temperature in whole degrees Celsius (rounded to the nearest whole number)
Td – Dew Point Temperature in whole degrees Celsius. (Rounded to the nearest whole
number)
QPHPHPHPH QNH
Q - indicator for QNH
PHPHPHPH - Pressure reduced to sea level. Reported as a whole number (ignoring the tenth
digit). Measured in hecto Pascal (HPa), 1 Hpa = 1 mB(millibar)
REw'w' shall only be included as recent weather IF the same phenomenon of the same or
greater intensity is not reported as present weather.
e.g.1 A heavy rainshower 20 minutes before the time of observation, with moderate rain
at the time of observation, shall be coded RERA.
e.g.2 Moderate rain 20 minutes before the time of observation, with a moderate rain
shower at the time of observation, shall not be coded as REw'w'.
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SPECI Special METAR criteria
A SPECI is the same as a METAR but issued when the following criteria is met:
1) When the mean surface wind direction has changed by 60° or more from that given in
the latest report, the mean speed before and/or after the change being (10 kt) or more
2) The mean surface wind speed has changed by 10Kt or more from that given in the latest
report .
3) The variation from the mean surface wind speed (gusts) has changed by (10 kt) or more
from that at the time of the latest report, the mean speed before and/or after the
change being (15 kt) or more.
4) Visibility changes to or passes:
i. 800, 1 500 or 3 000 m (SPECI) - 150, 350, 600, 800,1500, 3000m (TAF)
ii. 5000m where significant numbers of VFR flights are operating.
5) Runway visual range changes to or pass 150, 350, 600, 800m.
6) When the onset, cessation or change in intensity of any of the following weather phenomena
occurs:
— freezing precipitation
7) When the onset or cessation of any of the following weather phenomena occurs:
— freezing fog
— duststorm
— sandstorm
— squall
8) When any combination of weather in the significant weather table begins, ends or
changes intensity.
9) Height of the base of the lowest cloud layer of BKN or OVC extent, changes to or passes:
i. 100, 200, 500 or 1000ft.
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ii. 1500ft where significant numbers of VFR flights are operating.
10) When the amount of cloud below 1500ft changes from:
i. from SCT or less to BKN or OVC
ii. from BKN or OVC to SCT or less
11) When the sky is obscured and vertical visibility changes to or passes:
i. 100, 200, 500, 1000ft.
12) Increase in temperature of 2 degrees Celsius or more.
TAF
or NIL
TAF AMD CCCC YYGGggZ or dddffGfmfmKT
or Y1Y1G1G1/Y2Y2G2G2 or
TAF COR CNL
NsNsNShshshs
VVVV wlwl or VVhshshs
or or NSC
CAVOK
PROBC2C2 or
PROBC2C2 TTTTT YYGG/YeYeGeGe VVVV wlwl NSNSNShshshs
or TTTTT dddffGfmfmKT or or VVhshshs
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or or NSW or NSC
TTYYGGgg
CAVOK
(TXTFTF/YFYFGFGFZ TNTFTF/YFYFGFGFZ)
AMD Amended
Amendments or changes made to previous TAF.
COR Corrected
Correction/s was made to the TAF.
CCCC Location or Place - Four letter ICAO ID's designators are is used. (see: Locations)
NIL Missing
If not available or not received.
Y1Y1G1G1/Y2Y2G2G2
Y1Y1 Date of validity of the start of the TAF
G1G1 Time at start of TAF validity
Y2Y2 Date of validity of the end of the TAF
G2G2 Time at end of TAF validity
CNL Cancelled
TAF was cancelled. This may be due to the following reasons:
1. No observation (METAR) available.
2. TAF could not be kept under constant review.
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ff – Average Wind Speed in Knots (KT) within the preceding 10 minutes
G - GUST
fmfm – Highest wind speed (gust) within the preceding 10 minutes
KT - Knots
NOTE
a) VRB - Variable
Used when the windspeed is less than 3KT
Or during a violent thunderstorm when wind direction cannot be determined.
b) Gust is added only if the average wind speed is exceeded by 10KT or more of the mean
wind speed for previous 10 minutes (1KT = 1.85 Km/h).
CAVOK.
Coded in place of the visibility, present weather and cloud groups when the following conditions
occur simultaneously at the time of observation:
NsNsNshshshs Clouds (see also: CAVOK, NSC, Cloud Type, Cloud Atlas)
NsNsNs Cloud amount
The following abbreviations are used:
FEW - 1 to 2 octas
SCT - 3 to 4 octas
BKN - 5 to 7 octas
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OVC - 8 octas
wlwl Forecast weather which are deemed significant to the aircraft operations
Using the appropriate abbreviations (see ww), forecast weather is restricted to the occurrence of
one or more, up to a maximum of three, of the following weather phenomena, together with
their characteristics:
Freezing (FZ) precipitation;
Freezing fog;
Moderate or heavy precipitation (including showers –SH);
Low drifting (DR) dust, sand or snow;- Duststorm (DS);
Sandstorm (SS);
Thunderstorms (TS);
Squall (SQ);
Funnel cloud (tornado or waterspout –FC);
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Other weather phenomena given in code table 4678 which are expected to cause a significant
change in visibility.
YYGG/YeYeGeGe.
YY is the date and GG time of start of expected change
YeYe is the date and GeGe time of end of expected change
TTYYGGgg.
TT = FM = Expected change expected FROM a specific time
YY = Date of expected change
GG = Time in hours of expected change
gg = Time in minutes of expected change
TXTFTF/YFYFGFGFZ.
TX = Forecast maximum temperature to follow
TfTf = Forecasted maximum temperature in o Celcius
YfYf = Date of forecasted maximum temperature
GfGfZ= Hour in UTC of forecasted maximum temperature
TNTFTF/YFYFGFGFZ.
TN = Forecast minimum temperature to follow
TfTf = Forecasted minimum temperature in o Celcius
YfYf = Date of forecasted minimum temperature
GfGfZ= Hour in UTC of forecasted minimum temperature
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Sigwx Charts The only other cloud abbreviations used in Sigwx charts besides CB and TCU:
ST – Stratus
SC - Stratocumulus
CU – Cumulus
NS – Nimbostratus
AC – Altocumulus
AS - Altostratus
Cloud types not significant to aviation and are not in any aviation forecasts:
Ci – Cirrus Cs – Cirrostratus Cc – Cirrocumulus
METAR Examples
METAR FALE 271130Z 19017KT 9999 SCT025 BKN045 26/20 Q1015 NOSIG=
Explanation:
Report for station FALE: King Shaka Intl Airport, South Africa 29.3652S 031.0711E
Observation time: [Day: 27] [Time: 11:30 GMT or 13:30 SAST]
Wind speed: 17kt (8.7 m/s)
Wind direction: 190°
Visibility: 10km or more
Clouds: Scattered Clouds (3 to 4 oktas) 2500ft agl
Clouds: Broken Clouds (5 to 7 oktas) 4500ft agl
Air Temperature: 26° C
Dew-Point Temperature: 20° C
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Observed QNH: 1015 hPa
NOSIG No significant change is expected in the next two hours
SPECI FAOR 081340Z 19013G29KT 160V220 3000 -TSRA BR FEW014 SCT036CB 13/12 Q1020
TEMPO 1500 BKN010=
Explanation:
Forecast for station FAOR: O R Tambo Intl, South Africa 26.09S 028.1348E
Observation time: [Day: 08] [Time: 13:40 GMT or 15:40 SAST]
Wind speed: 13kt (6.5 m/s)
Wind direction: 190°
Wind direction variation: varying between 160o and 220o
Visibility: 3km
Present Weather: Light Thundershower with rain; mist
Clouds: Few Clouds (1 to 2 oktas) 1400ft agl
Clouds: Scattered Clouds (3 to 4 oktas) 3600ft agl ; Cumulonimbus clouds
Air Temperature: 13° C
Dew-Point Temperature: 12° C
Observed QNH: 1020 hPa
TREND A temporary change with the visibility being reduced to 1500m and
broken clouds (5-7octas) 1000ft agl is expected in the next two hours.
TAF Examples
Temporary Time: [Day 27 10:00 UCT or 12:00 SAST] Until time: [Day 27 15:00
UCT or 17:00 SAST]
Horizontal visibility: 5000 metres
Weather: Moderate Rain
Broken Clouds (5 to 7 oktas) at 300 meters (1000ft) AGL
Maximum Temperature 23 at Day 27 12:00 UCT or 14:00 SAST
Minimum Temperature 20 at Day 27 18:00 UCT or 20:00 SAST
The South African Weather Service uses ICAO codes for all aviation forecasts.
Familiarize yourself with these codes in order to understand the forecasts better.
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