Satellite radiance data assimilation enhancements for RRFS version 1

Global Systems Laboratory (GSL) is working in conjunction with NCEP/EMC toward the planned operational implementation of the Rapid Refresh Forecast System (RRFS), including enhanced satellite radiance assimilation capabilities. RRFS is planned to be operationally implemented in 2025, as part of the FV3 model-based Short-Range Weather (SRW) application of the Unified Forecast System (UFS).

We are currently testing/finalizing the radiance data assimilation updates (including the direct broadcast capabilities) for the RRFS version 1 (RRFSv1) implementation. In order to save computational cost for hourly cycled retrospective testing, we have worked a lot with 13-km resolution domain covering a large RAP like region (slightly larger than the planned 3-km North American RRFS domain). In addition to all radiance data currently assimilated in the operational Rapid Refresh (RAP), the planned radiance updates for RRFSv1 also include the assimilation of some new data sets (e.g., NOAA-21 CrIS-FSR/ATMS, GOES-18 ABI, etc.). The total radiance data impact as well as individual impact from assimilation of these new data sets are evaluated through a series of prototype RRFS retrospective runs. Finally, we are testing and evaluating radiance data assimilation for the 3-km North America RRFS. At the conference, we will present and report on the radiance updates planned for RRFSv1 as well as radiance data impact within RRFS.