Rapid Refresh (weather prediction)

The Rapid Refresh (RR or RAP) is a numerical weather prediction (NWP) model. The model is designed to provide short-range hourly weather forecasts for North America. The Rapid Refresh was officially made operational on 1 May 2012, replacing the Rapid Update Cycle (RUC). The model also serves as the boundary conditions for the higher-resolution High Resolution Rapid Refresh (HRRR) model, that uses a 3 km (1.9 mi) grid spacing on a domain covering the continental United States.[1][2][3]

The Rapid Refresh is run at the NOAA National Centers for Environmental Prediction (NCEP). It is based on the framework of the Weather Research and Forecasting model (WRF); the Global Forecast System (GFS) provides the boundary parameters. The grid points are spaced every 13 kilometres (8.1 mi), with 50 vertical intervals extending up to the 10-hectopascal (10 mb) level of the atmosphere. The model runs once each hour, with forecasts given hourly out to 18 hours.[2][3]

An experimental version of the Rapid Refresh runs at the Earth System Research Laboratory (ESRL), a NOAA unit that develops models in the research stage prior to operational implementation at NCEP.[2]