Does Increasing Horizontal Resolution Produce More Skillful Forecasts?

This paper examines the impacts of increasing horizontal resolution on the performance of mesoscale numerical weather prediction models. A review of previous studies suggests that decreasing grid spacing to approximately 10 km or less generally produces more realistic mesoscale structures, with particular benefits for orographically and diurnally driven flows. There have been only a few long-term objective verification studies of high-resolution forecasts, and these studies suggest, perhaps deceptively, that there are diminishing returns as horizontal grid spacing decreases below approximately 10 km. A multiyear objective verification of the University of Washington MM5 real-time forecasting system compares…

• NS
  National Science Foundation