A storm’s intensity is measured in dBZ, which is a logarithmic, dimensionless, technical unit used in radar. For details on the scale see the table below.
| dBZ | Rate (mm/hour) | Rate (inches/hour) | Intensity |
|---|---|---|---|
| 5 | 0.07 | < 0.01 | Hardly noticeable |
| 10 | 0.15 | < 0.01 | Light mist |
| 15 | 0.3 | 0.01 | Mist |
| 20 | 0.6 | 0.02 | Very light |
| 25 | 1.3 | 0.05 | Light |
| 30 | 2.7 | 0.10 | Light to moderate |
| 35 | 5.6 | 0.22 | Moderate rain |
| 40 | 11.53 | 0.45 | Moderate rain |
| 45 | 23.7 | 0.92 | Moderate to heavy |
| 50 | 48.6 | 1.90 | Heavy |
| 55 | 100 | 4 | Very heavy/small hail |
| 60 | 205 | 8 | Extreme/moderate hail |
| 65 | 421 | 16.6 | Extreme/large hail |