Precipitation effects adjust tree growth based on plot precipitation.
| Weibull Precip Effect "A" | The A parameter for the precipitation effect. Units of precipitation are millimeters per year. |
| Weibull Precip Effect "B" | The B parameter for the precipitation effect. Units of precipitation are millimeters per year. |
| Weibull Precip Effect "C" | The C parameter for the precipitation effect. Units of precipitation are millimeters per year. |
| Precipitation Type to Use | Which precipitation variable should be used. |
Precipitation Effect is calculated as:

where:
The desired precipitation variable is set in the Precipitation Type to Use variable.
| Double Logistic Precip Effect "al" | The al parameter for the precipitation effect. |
| Double Logistic Precip Effect "bl" | The bl parameter for the precipitation effect. |
| Double Logistic Precip Effect "cl" | The cl parameter for the precipitation effect. |
| Double Logistic Precip Effect "ah" | The ah parameter for the precipitation effect. |
| Double Logistic Precip Effect "bh" | The bh parameter for the precipitation effect. |
| Double Logistic Precip Effect "ch" | The ch parameter for the precipitation effect. |
| Precipitation Type to Use | Which precipitation variable should be used. |
Precipitation Effect is calculated as:

where: