There are models that predict precipitation amounts and river/lake stage (level), yes, but usually it’s up to the lead meteorologist to make the call after reviewing those models combined with their experience with the situation. Precip rate is also an output of some forecast models that is considered when issuing an advisory. These models consume huge amounts of data that influence the output prediction in complex, chaotic ways. Better quality data can often produce better forecasts and lead to better decisions but whether or not the specific event would have had a better outcome is harder to answer.