ir - Indicator for precipitation
Always code figure 4.
ix - Indicator for weather group
Always code figure 1 (group 7wwW1W2 included).
h - Height of base of lowest cloud in the sky
If the sky is not visible owing to fog, or if height is unknown, then / is reported. If there is fog,
and the sky is visible through it, the cloud is reported as if no fog were present. A height
exactly equal to one of the heights in the table is reported by the higher code figure.
Code Height (feet) Height (metres)
0 0 to 150
0 to 50
1 150 to 300
50 to 100
2 300 to 600
100 to 200
3 600 to 1,000
200 to 300
4 1,000 to 2,000 300 to 600
5 2,000 to 3,000 600 to 1,000
6 3,000 to 5,000 1,000 to 1,500
7 5,000 to 6,500 1,500 to 2,000
8 6,500 to 8,000 2,000 to 2,500
9 8,000 or more or no cloud 2,500 or more or no cloud
- Because cloud is not reported
by auxiliary ships, h is coded with a solidus (/).
VV - Horizontal visibility
If visibility varies in different directions then the shorter distance is coded.
Code Visibility (km) Visibility (nautical miles)
90 < 50 m < 0.03
91 50 m 0.03
92 0.2 0.1
93 0.5 0.3
94 1 0.5
95 2 1.1
96 4 2.2
97 10 5.5
98 20 11
99 >= 50 >= 27
Note
- If the observed horizontal
visibility is between two of the distances given in the table, the
code figure for the shorter distance is reported, e.g. if the distance is estimated to be
between 0.3 and 0.5 nautical miles the code figure 93 is reported.