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Rapid Refresh/Rapid Update Cycle

The Rapid Refresh (RAP) numerical weather model replaced the Rapid Update Cycle (RUC) on May 1, 2012. The National Centers for Environmental Prediction (NCEP) runs two different versions of RAP. The first generates weather data on a 13-km (8-mile) resolution horizontal grid and the second, the High-Resolution Rapid Refresh (HRRR), generates data down to a 3-km (2-mile) resolution grid for smaller regions of interest. RAP forecasts are generated every hour with forecast lengths up to 18 hours.

An animated 3-D plot of RAP forecast data valid from 0000 UTC through 1800 UTC on July 11, 2012. This forecast loop shows simulated composite radar reflectivity on the surface and a 25 m/s isosurface of wind speeds aloft. Stretching from Hudson's Bay to the Atlantic is a vertical profile of relative humidity, red showing high relative humidity and blue showing drier air. This image was generated with Unidata's Integrated Data Viewer (IDV).

Access Methods

NCEI model data services provide access to RAP forecast and analysis data. HRRR data are available through the HRRR home page. The NOAA Big Data Program also provides access to HRRR data in a trailing 30-day window in the AWS Open Data Registry for HRRR.

RAP Analysis

Specifications

  • Period of Record: 01 May 2012–Present
  • Model Cycle: 24/day: 00, 01, 02,... 23UTC
  • Output Timestep: +000 and +001 hours

Data and Files

RAP Analysis Data
Grid/Scale Files Data Access Links
130 (13km)
252 (20km)

RUC Analysis

Specifications

  • Period of Record: 01Jan2005–01May2012
  • Model Cycle: 24/day: 00, 01, 02,... 23UTC
  • Output Timestep: +000 and +001 hours

Data and Files

RUC Analysis Data
Grid/Scale Files Data Access Links
130 (13km)
252 (20km)

RAP Forecasts

Specifications

  • Period of Record: 01 May 2012–Present (approx. one year to present online)
  • Model Cycle: 24/day: 00, 01, 02,... 23UTC
  • Output Timestep: Hourly, +000 to +018 hours
RAP Forecast Data
Grid/Scale Files Data Access Links
130 (13km)
252 (20km)

RUC Forecasts

Specifications

Model Cycle: 24/day: 00, 01, 02,... 23UTC

RUC Forecast Data
Grid/Scale | Period of Record Files Output Timestep Data Access Links
130 (13km) | 24/day: 00, 01, 02,... 23UTC Hourly, +000 to +012 hours AIRS
252 (20km) | 24/day: 00, 01, 02,... 23UTC Hourly, +000 to +012 hours AIRS
252 (20km) | 01Jan2005–21Feb2008 (GRIB1) Hourly, +000 to +012 hours AIRS
236 (40km) | 01May2002–05Jul2005 Hourly, +000 to +012 hours HTTPS
211 (81km) | 01May2002–05Jul2005 3-hourly, +000 to +012 hours HTT

Resources

Data Sources

  • Commercial Aircraft
  • Weather Balloons 
  • Radar 
  • Surface Observations
  • Satellite 

Data Usage Notes

April 2003: RUC Grid 211 Forecast Hour 02 Labeled as Analysis Field

Messages for RUC2 will contain multiple records and one of the records will contain data from a forecast hour. The messages below belong to the RUC2 grid 236 2200UTC model runs on April 5th and April 6th of 2003. In the headers below, octet 4 indicates the forecast hour. The letter "A" indicates the 00 hour analysis, but according to wgrib the messages contain records with a 2-hr forecast.

YUWA98_KWBG_20030405_2200 
1:21:d=03040522:UGRD:10 m above gnd:anl:NAve=0 
2:19332:d=03040522:USTM:sfc:anl:NAve=0 
3:38643:d=03040522:USTM:sfc:2hr fcst:NAve=0 
YVWA98_KWBG_20030405_2200 
1:21:d=03040522:VGRD:10 m above gnd:anl:NAve=0 
2:19332:d=03040522:VSTM:sfc:anl:NAve=0 
3:38643:d=03040522:VSTM:sfc:2hr fcst:NAve=0 
YWWA98_KWBG_20030405_2200 
1:21:d=03040522:CAPE:sfc:anl:NAve=0 
2:27864:d=03040522:var180:sfc:anl:NAve=0 
3:38643:d=03040522:var180:sfc:2hr fcst:NAve=0

March 2003: All RUC Grid 211 Analysis Fields Labeled as Global Forecast System Aviation Model

Messages from the RUC model grid 211 analysis fields have World Meteorological Organization (WMO) headers that indicate they are from the Global Forecast System Aviation (GFS-AVN) model. All the RUC grid 211 forecast hour 00 messages are missing because they are stored with the GFS-AVN grid 211 forecast hour 00 data. In the example below the "KWBC" in the WMO header indicates the GFS-AVN model, but the process id "86" indicates the RUC model.

nomads3.ncdc.noaa.gov 51: wgrib -V YVQA99_KWBC_20030801_0000 
rec 1:21:date 2003080100 VGRD kpds5=34 kpds6=100 kpds7=1000 
levels=(3,232) 
grid=211 1000 mb anl: bitmap: 1713 undef 
VGRD=v wind [m/s] 
timerange 0 P1 0 P2 0 TimeU 1 nx 93 ny 65 GDS grid 3 num_in_ave 0 missing 0 
center 7 subcenter 0 process 86 Table 2 
Lambert Conf: Lat1 12.190000 Lon1 -133.459000 Lov -95.000000 
Latin1 25.000000 Latin2 25.000000 LatSP 0.000000 LonSP 0.000000 
North Pole (93 x 65) Dx 81.271000 Dy 81.271000 scan 64 mode 8 
min/max data -11.6 9.8 num bits 8 BDS_Ref -116 DecScale 1 
BinScale 0