Precipitations falls | DIs Ranges (%) | Justification |
10% - 20% | 1 to 2 | Much below normal |
30% - 40% | 3 to 4 | Below normal |
40% - 60% | 5 to 6 | Near normal |
60% - 80% | 7 to 8 | Above normal |
80% - 100% | 9 to 10 | Much above normal |