| Precipitation efficiency (PE) is measured as a ratio of output moisture to input moisture. In this experiment, four distinct methods of estimation were used to calculate PE with two distinct warm-season heavy rainfall events using Rapid Update Model (RUC) gridded datasets. All calculations were performed internally within the model for consistency. While some methods produced values between 0 and 100%, some of the methods provided instantaneous PE values of greater than 100%, while still others yielded a negative value. Methods were compared by instantaneous point value and area average values using a Pearson linear correlation. The data was combined for an overall correlation. The greatest correlation was 0.86 and 0.35 for short and long-lived events respectively, indicating that there is no robust way of estimating PE. The statistics also show little correlation with precipitation values indicating that a highly efficient system does not necessarily indicate that a large quantity of precipitation fell. |
