Rapid Refresh (RAP)

The Rapid Refresh is the continental-scale NOAA hourly-updated assimilation/modeling system operational at NCEP. RAP covers North America and is comprised primarily of a numerical forecast model and an analysis/assimilation system to initialize that model. 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.

• RAPv1 - implemented 1 May 2012 at NCEP (replacing the Rapid Update Cycle - RUC )
• RAPv2 - implemented 25 Feb 2014 at NCEP
• RAPv3 - implemented 23 Aug 2016 at NCEP
• RAPv4 - implemented 12 July 2018 at NCEP
• RAPv5 - implemented 12z Wed 2 Dec 2020 at NCEP
  (run experimentally at GSD since spring 2019)
  Information available in RAPv5/HRRRv4 summary - Jan 2020

NCEP implementations of 3km HRRR

version 1 - 30 Sept 2014

version 2 - 23 Aug 2016

version 3 - 12 July 2018

version 4 - IMPLEMENTED 12z Wed 2 Dec 2020
(run experimentally at GSD/GSL since spring 2019)

Complete RAP (v1-v3) description in Benjamin et al. 2016, A North American Hourly Assimilation and Model Forecast Cycle: The Rapid Refresh. Mon. Wea. Rev., 144, 1669-1694. Recent RAP/HRRR presentations

• HRRR/RAP July 2016 presentation to NWS

High-Resolution Rapid Refresh (HRRR - 3km)

• HRRR home page / info
• Real-time products from 3km HRRR

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Access to real-time and archive RAP grids

NCEP ftp site for real-time RAP data in GRIB2 format

NCEP RAP product inventory

NWS/COMET archive of RAP hybrid (native) grids