Preliminary Evaluation of Real-Time, 8-Day, Convection-Allowing Ensemble Forecasts over the Conterminous United States

Coincident with NOAA’s Hazardous Weather Testbed Spring Forecast Experiment in May 2023, real-time, 8-day, 10-member ensemble forecasts were produced with GFDL’s “C-SHiELD”, a prediction model based on the Finite-Volume Cubed-Sphere Dynamical Core (FV3). These forecasts had ~3-km horizontal grid spacing over the conterminous United States (CONUS) and ~13-km horizontal grid spacing over the rest of the globe. Forecasts were initialized at 0000 UTC from Global Ensemble Forecast System initial conditions. All 10 ensemble members had identical physical parameterizations, with diversity achieved solely by different initial conditions.

This poster will provide preliminary objective verification statistics from these forecasts, focusing on medium-range (3–8-day) severe weather and precipitation forecast quality over the CONUS.