Evaluating FV3 Performance during the Spring Severe Convection Season

The Finite Volume Cubed Sphere (FV3) model is slated to replace the GFS in 2019 and will eventually become the core around which NOAA’s systems unify. As such, research and development at convection-allowing scales is needed to understand the convective characteristics of storms in the FV3. During the 2017 and 2018 NOAA Hazardous Weather Testbed (HWT) Spring Forecasting Experiments (SFE), versions of FV3 with a nested 3-km grid over the CONUS were run on a daily basis alongside other model guidance within the Community Leveraged Unified Ensemble (CLUE), providing a dataset from which the performance of FV3 can be evaluated.

This work evaluates the overall performance of FV3 during severe convective weather objectively using surrogate severe techniques and output from the Model Evaluation Tools (MET) software package. Fields such as updraft helicity, reflectivity, and environmental characteristics will be considered daily, as well as in aggregate for the duration of the SFEs. The FV3 output will also be evaluated subjectively using results from evaluations completed during the 2018 SFE. Differences between the FV3 and other guidance from the CLUE will be explored, particularly those that are highlighted in the results from the subjective evaluations.