Advanced Historical Forcings: Application of the Analysis of Record Gridded Data for Hydrologic Calibrations Across the Northwest U.S.

Development of forcing (i.e. precipitation and temperature) data for operational hydrologic forecasting remains an ongoing challenge, as it requires an interdisciplinary knowledge-base to acquire, quality-control, assimilate, and synthesize multiple sources (e.g. weather stations, radar, etc.). Until recently, the National Weather Service (NWS) Northwest River Forecast Center (NWRFC) generated historical forcing data internally using observations from weather stations with a weighting scheme. However, a newly available forcing dataset has the potential to supersede the traditional approach. The Analysis of Record (AOR) was generated by the NWS Office of Water Prediction (OWP) as a gridded (1 km) product with an hourly temporal resolution spanning more than 35 years. In this work, we present comparisons (e.g. seasonal, spatial, etc.) between the two datasets, and discuss validation criteria regarding the applicability of using AOR as a forcing source for hydrologic model calibration. The discussion will touch on the potential of the AOR dataset to provide future model enhancement opportunities, and why coordinated dialog with regional stakeholder (e.g. weather forecast offices, water resource managers, etc.) will be essential with any large-scale modeling changes.