Evaluation of Forecast Performance of a Prototype JEDI-Based GDAS

Currently, the Global Data Assimilation System (GDAS) at the National Centers for Environmental Prediction (NCEP) uses the Gridpoint Statistical Interpolation (GSI) software for computing operational atmospheric analyses. As part of the transition to the Unified Forecast System (UFS), GSI is slated to be replaced by a Unified Data Assimilation (UDA) framework based on the Joint Effort for Data assimilation Integration (JEDI). Efforts are underway at NCEP on replacing all GSI-based assimilation components with JEDI-based components for a future implementation of the GDAS. Here we present an evaluation of atmospheric model forecast performance of a prototype JEDI-based cycling version of the Global Forecast System (GFS) relative to a comparable GSI-based configuration of the GFS as well as the operational system. This study will assess a variety of meteorological metrics using evaluation tools for both short (6 hour) and medium (5 day) range forecast performance for the month of August 2021. The forecasts will be evaluated on global as well as regional domains with comparisons to observational data and operational analyses. The goal of this research is to evaluate forecast performance within the JEDI-based cycling forecasts to ensure it is comparable to the current GSI-based configuration and identify areas for future verification efforts.