The High-Resolution Rapid Refresh (HRRR)


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Composite Reflectivity
The HRRR is an experimental real-time 3-km resolution, hourly updated, cloud-resolving atmospheric model, initialized by DFI-fields from the 13km radar-enhanced Rapid Refresh (ESRL version, not NCEP version) starting 14 April 2011 replacing the previous Rapid Update Cycle (RUC) as the HRRR initial conditions.

A full description on the HRRR system (assimilation, model configuration, verification, applications) presented on 13 March 2012 is available here. The HRRR is run at NOAA/ESRL/GSD as a real-time demonstration.

    The HRRR uses
  • a configuration of the WRF model, updated significantly in Jan-March 2012, similar to that used for the Rapid Refresh (ARW core, Thompson microphysics, RUC-Smirnova land-surface model, etc., as defined here), but without any convective parameterization.
  • initialized with latest 3-d radar reflectivity via the 13km hourly updated model (Rapid Refresh run at ESRL/GSD starting 14 April 2011 22z, prior to that time from 13km backup RUC at ESRL/GSD). The 13km assimilation/model systems (RAP or RUC) both include radar reflectivity assimilation via radar-DFI (digital filter initialization) technique.
  • 24 Nov 2012 - A development version of the HRRR model run on the NOAA research supercomputer zeus has real-time products available under http://rapidrefresh.noaa.gov/hrrr_dev1 . Products from this development version are often available during outages of the primary HRRR model run.
  • 9 March 2012 - The 2012 HRRR configuration and 2012 ESRL Rapid Refresh configuration has been finalized after a number of changes from December 2011 through early March 2012.
  • 25 July 2011 - HRRR forecasts being used for experimental renewable energy guidance under the DOE/NOAA Wind Forecast Improvement Project (WFIP) with verification against WFIP profilers and sodars.
  • 7 July 2011 - Addition of PBL-based pseudo-innovations to the Rapid Refresh initializing the HRRR at 00z 7 July. More information available at http://ruc.noaa.gov/pdf/RR-HRRR-PBL-pseudo-obs-6jul2011.pdf
  • 14 April 2011 - HRRR parent model changed from RUC to Rapid Refresh. RR has improved larger-scale forcing (more accurate 3-18h forecasts for wind/temp/RH). 0h HRRR reflectivity (actually 1h forecast from 13km model) have much improved consistency with HRRR forecasts now with the RR parent.
  • 9 October 2009 - HRRR domain expanded again to full CONUS coverage. Products available at http://rapidrefresh.noaa.gov/hrrrconus .
  • 25 March 2009 - now runs over a domain covering approximately the eastern 2/3 of the lower 48 US, about 2.4x larger than the previous NE Corridor domain. NE Corridor HRRR products are now subset from the larger HRRR runs. Advantages of larger domain:
    • Coverage for hourly HRRR forecasts extended through midwest and southern U.S.
    • Boundary transition zones extended far from key aviation hubs, including ORD, MSP, ATL, and others.
  • no separate data assimilation, relying instead on radar-assimilating RUC.
  • 1-way nest inside RUC (including cloud hydrometeors specified on lateral boundaries)
  • A fully operational version of the HRRR at NCEP is planned but not earlier than 2014 when NCEP computing resources will allow this addition.
    An interactive-chemistry version of the HRRR is now being run every 6h over the western US with real-time fire information (GOES ABBA) to provide air quality guidance (as of Aug08),
  • Same radar-enhanced RR-DFI (before 14 Apr 2011 - RUC-DFI) grids as atmospheric initial conditions, same as hourly HRRR.
  • Cycled chemistry variables, including 3-d ozone, PM 10 aerosol, PM 2.5 aerosol.
  • Adding WRF-chem to other parameterizations used in NE Corridor HRRR
The HRRR is the only hourly updated, radar-initialized, storm-resolving model running at this time over the US (or internationally), to our best knowledge.
    As a higher-resolution nest inside the hourly-updated Rapid Refresh (and before 4/14/2011, RUC), the HRRR is designed to
  • provide rapidly updated model guidance on convective storms for
    • air traffic management
    • severe weather forecasting
    • NOAA National Weather Service Warn-On Forecast
  • eventually provide improved background fields for NWS Real-Time Mesoscale Analysis
  • provide improved basis for other aviation hazard forecasts (e.g., wake vortex, ceiling, visibility, turbulence, inflight icing, terminal forecasts)
  • The HRRR is fully dependent on the hourly-updated, radar-assimilating Rapid Refresh and prior to 4/14/2011, the radar-enhanced Rapid Update Cycle (RUC) , as shown in daily comparisons of 3km model runs with and without the 13km radar-reflectivity assimilation in the RUC/RR.