2026/07/28 by Andrew H. Berrington, Keith Brewster, Keith A. Brewster +6
Earth and Planetary Sciences · Environmental Science · #Climate variability and models #Meteorological Phenomena and Simulations #Precipitation Measurement and Analysis
paper · pdf · doi:10.1175/waf-d-25-0256.1
openalex publication_date 2026/07/28 · openalex created_date 2026/07/29 · openalex updated_date 2026/07/30
Abstract A 15-member experimental ensemble using the FV3-LAM dynamic core is evaluated for precipitation forecasting during Summer 2024. The ensemble was run once daily out to 84 hours lead, for a total of 30 days, in support of the NOAA Hydrometeorological Testbed’s Flash Flood and Intense Rainfall Experiment. It employs a variety of physics combinations, boundary conditions, radar data assimilation, and cumulus convective schemes. Evaluation via contingency table metrics suggests that activating cumulus convective schemes, in conjunction with GEFS boundary conditions, may have a detrimental effect on precipitation forecasts beyond day 1. Additionally, greater biases are noted in members using the Noah-MP land surface scheme than others. Radar reflectivity data assimilation improves ensemble performance on day 1, while a re-alignment of features to a common position among members (Spatial Aligned Mean) improves performance of ensemble consensus products. An experimental MPAS member run alongside the FV3 ensemble shows competitive performance out to day 2, with slightly worse performance during days 3 and 4. The results helped inform ongoing RRFS development during and after the experiment. Recommendations based on these results are subsequently made for future model development and forecast experiments.