IMPLEMENTATION OF OBSERVATION-NUDGING BASED FDDA INTO WRF FOR SUPPORTING ATEC TEST OPERATIONS

Abstract

In the last few years, NCAR and the Army Test and Evaluation Command (ATEC) have jointly developed a real-time rapid-cycling FDDA and forecast (RTFDDA) system. This MM5-based system has been deployed and is running operationally at five Army testing ranges. The ATEC RTFDDA data assimilation procedure was developed based on the observation-nudging scheme in the standard MM5 (Stauffer and Seaman 1994). It was imported into the WRF model as a part of the ATEC modeling transition from the MM5 to WRF framework. The basic code porting was completed in April 2005. Since then, the WRF-FDDA system has been tested with real-time cycling for the Dugway Provide Ground (DPG), in parallel with the MM5-based RTFDDA system running at the range. To achieve a fair comparison between the WRFand MM5based systems, the WRF model is configured to have the same domain configurations and similar physics to those of the operational MM5.