The plot details are as follows.
#1 Cloud Coverage
A pie chart showing coverage in oktas (that is, eights) of sky coverage drawn using standard
symbols. The example shows 6 oktas.
Because METAR messages do not give cloud cover in oktas units, METAR text is mapped as
follows:
METAR message Oktas
SKC or CLR 0 oktas
FEW
1 okta
SCT
3 oktas
BKN
6 oktas
OVC
8 oktas
Figure 70 Okta Standard Symbols
#2 Wind Barb
A line with feathers showing the wind speed and direction, to the nearest 5 knots.
A knot (nautical mile per hour) is close to half a meter/second, so 20 knots would be 10 m/s.
The line points up wind. It has a half feather line for 5 knots, and full length lines for 10 knots,
and a triangular flag for 50 knots. If the wind speed is 0, then a circle is draw outside the sky
coverage circle.
The example shows a wind of 5 knots from the south.
#3 Present Weather
There is a large set of available symbols, shown in the following figure. The example in
Figure 68 (page 193) shows 2 dots, which means light rain.
Matching of METAR present weather text to symbols in Table 19 (page 196) is not
necessarily endorsed by the National Weather Service (NWS) or the World Meteorological
Organization (WMO).
IRIS Product and Display User Guide M211319EN-H
194 RESTRICTED
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