Rapid Refresh

The Rapid Refresh system (RAP) is an hourly-updated assimilation/modeling system running at 13 km resolution, developed at NOAA's Earth Systems Research Laboratory (ESRL). The RAP covers North America and is comprised of a numerical forecast with the Advanced Research WRF (WRF-ARW) model and an data assimilation system using the NCEP Gridpoint Statistical Interpolation (GSI) analysis. The RAP is complemented by the higher-resolution 3km High-Resolution Rapid Refresh (HRRR) model, which is also updated hourly and covering a smaller geographic domain. More information and hourly graphics from the RAP can be viewed at ESRL's RAP home page; HRRR information and graphics can be obtained at ESRL's HRRR home page 

RAP History at NCEP:

A description of versions 1-3 of the RAP can be found in Benjamin et al. 2016, A North American Hourly Assimilation and Model Forecast Cycle: The Rapid Refresh. Mon. Wea. Rev., 144, 1669-1694.

Official RAP and HRRR graphics from the operational runs can be found at the NCEP Model Analysis and Guidance (MAG) web site.