Information is only one factor, as rain in the forecast, then the precision is reduced when it is applied to the areas that have the ability to remove the rain catchment.
Bringing rain only a single factor as the basis for the forecast. Precision is diminished when applied to areas that have the ability to keep rainwater out a lot.
The rainfall data only one factor as the criterion for forecasting. Accuracy will be reduced when used with space capable of storing rainwater in a lot.