The Office of Water Prediction's Analysis of Record for Calibration, version 1.1: Dataset description and precipitation evaluation

Hydrologic models operated by the National Weather Service call for an accurate, consistent, high-resolution, multi-decade, continental-scale record of hydrometeorological fields to serve as forcing data for model calibration. To serve this purpose, the Analysis of Record for Calibration was developed, and version 1.1 of the dataset is described in this study. Geospatial and scientific requirements, methods used in dataset generation, and input data sources are described. Given the prominent role of precipitation in model calibration, accurate and consistent precipitation is a particularly high priority for the analysis. To evaluate the analysis from this perspective, its daily precipitation is compared with surface observing stations over 43 years. The analysis exhibits low bias compared with other similar products. It also displays nonstationary bias behavior after 2015 due to the lack of a climatological constraint, as well as frequent occurrences of heavy-to-extreme precipitation that are often difficult to verify. These findings should be taken into account when the product is used for model calibration.