0 0 NIL           IN CLOUD
1 1 SLIGHT        IN CLOUD
2 2 MODERATE      IN CLOUD
3 3 SEVERE        IN CLOUD
4 4 NIL           IN CLEAR AIR
5 5 SLIGHT        IN CLEAR AIR
6 6 MODERATE      IN CLEAR AIR
7 7 SEVERE        IN CLEAR AIR
15 15 MISSING VALUE
