0 0 NIL
1 1 LIGHT
2 2 MODERATE
3 3 SEVERE
4 4 NIL
5 5 LIGHT
6 6 MODERATE
7 7 SEVERE
8 8 NIL
9 9 LIGHT
10 10 MODERATE
11 11 SEVERE
12 12 EXTREME, IN CLEAR AIR
13 13 EXTREME, IN CLOUD
14 14 EXTREME, CLOUD/CLEAR AIR NOT SPECIFIED
15 15 MISSING VALUE
