The Rapid Update Cycle (RUC)
Precip/MSLP/1000-500 thick - 12h fcst
Aviation Flight Rules - 12h fcst
Tropopause Pressure - 12h fcst
- Modified 1 May 2012: The RUC was a NOAA/ NCEP
operational weather prediction system running every hour out to at least 18h
comprised primarily of
- A numerical forecast model (using isentropic-sigma hybrid vertical coordinate) and
- An analysis/assimilation system to initialize that model.
- Developed to serve users needing frequently updated short-range weather forecasts, including those in the US aviation community and US severe weather forecasting community.
- The Rapid Refresh (RAP) is the next-generation version of the 1-h cycle system, and replaced the operational RUC at NCEP at 12z on 1 May 2012.
- 8 May 2012 - An experimental version of the RUC continues to run at ESRL for an undetermined period of time but likely through much of 2012.
- 1 May 2012 RAP operational implementation at NCEP occurred at 12z on 1 May 2012 as planned. The last NCEP RUC run was 11z today.
- 19 Mar 2012 30-day Rapid Refresh evaluation completed with recommendations for implementation but due to other computer complications, the NCEP RAP implementation is now no earlier than 3 April 2012. More news will be posted as it becomes available.
- 14 Feb 2011 Rapid Refresh testing continuing at NCEP/EMC as well as at ESRL, NCEP implementation now planned for Oct-Nov (updated 7/22) 2011. The RAP is showing improvement over RUC forecasts for wind, RH, temperature, and heights at almost all levels and forecast durations. ftp access for RR grids is now offered by NCEP -- see this recent RUC forum post from Geoff Manikin at NCEP.
- 16 Sept 2010 Progress continuing with Rapid Refresh testing at ESRL (see http://rapidrefresh.noaa.gov ), real-time testing at NCEP underway.
- 2 March 2010 - RUC upgrade (although not completely installed until 20 April 2010. Explanation ): Extension of RUC to 18h every hour, modification to hybrid coordinate, addition of Canadian aircraft observations. More info available at http://www.nws.noaa.gov/om/notification/tin10-07aaa_ruc_changes.txt
- 4 Dec 2009 Problem with radar reflectivity ingest into NCEP-operational RUC starting early August, script updated to changed directory Tues 1 Dec.
- 12 Nov 2009 Rapid Refresh/RUC review presentation - latest news - PDF
- 14 Oct 2009 TAMDAR moisture observations restored to RUC (and NAM) for NCEP runs today after 50-day absence due to upstream metadata change. TAMDAR moisture observations have been available all along for all ESRL/GSD RUC runs.
- 31 Mar 2009. NCEP implementation at 12z with improved snow cover and improved cloud analysis, see Info PDF here. - February RUC forum post on this topic
- 16 Dec 2008. TAMDAR data added to operational RUC at NCEP
- 17 Nov 2008. RUC upgrade implementation at NCEP Assimilation of radar reflectivity added, longwave radiation changed to RRTM scheme, convection (Grell-Devenyi) changes. Extended RUC upgrade ppt here for pre-implementation briefing
- 8 Jan 2008. RUC crisis change for improved cloud/vis assimilation, wind gust, precip type. Post on RUC forum , PDF
- 11 Dec 2007. RUC/RR summary Powerpoint/pdf presented at NCEP Production Suite Review meeting.
- 4 Dec 2007. 13km/hourly RUC grids became available via NOAAPort and Family of Services. See RUC Forum post
- Reflectivity real-time products available for devRUC13 and backup RUC13 uns since April 2007.
- 4 April 07 - 3-d radar reflectivity data assimilated hourly in experimental devRUC13 since Feb07 and now in backup RUC13 as now. An example of the effect of radar reflectivity assimilation in available here
- 28 June 2005 --
13km RUC operational implementation at NCEP --
-- Higher resolution, additional observation types assimilated (GPS PW, METAR cloud/vis, RASS, improved use of GOES cloud-top), improved moisture analysis, improved cloud/precip physics.
RUC journal articles available in Feb 2004 Monthly Weather Review.
Mesoscale Weather Prediction with the RUC Hybrid Isentropic Terrain-Following Coordinate Model. pages 473-494. [GSD PDF version]
An Hourly Assimilation-Forecast Cycle: The RUC. pages 495-518. [GSD PDF version]
- high-frequency (every 1h) short-range weather model forecasts (out to 12+ h) in support of aviation and other mesoscale weather forecast users
high-frequency (every 1h) 3-d objective analyses
over much of North America,
including the contiguous United States and
adjacent areas of Canada and Mexico, assimilating the following types of observations:
- Commercial aircraft, including regional aircraft data with moisture (TAMDAR)
- Radar reflectivity (3-d)
- Profiler related
- Wind profilers (404 and boundary-layer 915 MHz)
- VAD (velocity-azimuth display) winds from NWS WSR-88D radars
- RASS (Radio Acoustic Sounding System)
- Rawinsondes and special dropwinsondes
- Surface reporting stations and buoys (including cloud, visibility, current weather)
- GPS total precipitable water estimates
- GOES cloud-top data (pressure and temperature)
- GOES total precipitable water estimates
- SSM/I total precipitable water estimates
- GOES high-density visible and IR cloud drift winds
- Lightning - experimental
- NASA Langley cloud products including water/ice path
- a hybrid isentropic-sigma vertical coordinate.
The key features of the RUC include:
Other RUC Information, Real-Time and Archived Data
- NCEP ftp site including 13km output resolution grids available in GRIB2 since summer 2007, see ftp://ftpprd.ncep.noaa.gov/pub/data/nccf/com/ruc/prod/
- More info - NOAA/NCEP - Real-time operational RUC grids
- NOAA/NWS/TG server NOAA/NWS/TG (Telecommunications Gateway) - real-time RUC grids
Archived RUC gridded data available from:
- RUC COMET archive for last 31 days
- Background on RUC data from DOE/ARM Program DOE/ARM web page on RUC gridded data (link corrected 7-22-2011)
- NASA Langley archived RUC soundings
- NCAR/UCAR - Access to archived GSD/FSL RUC/MAPS data for UCAR registered users (use search for 'MAPS')
Information on gridded data
- RUC grid files - Information on contents
RUC13 GRIB table-updated 17 Nov 2008
with RUC upgrade
(see RUC20 table for GRIB document links)
- Previous RUC13 GRIB table as of Sept 2005
- RUC20 GRIB table with GRIB document links
- RUC analysis obs and background error specifications
Model fixed fields - topography, etc.
Download RUC fixed fields (ASCII) and software
- 13km topography, mini-topography, lat/lon, land-use, roughness length, soil type
- 5km RTMA topography (used for RUC-RTMA downscaling)
- 20-km, 40-km and 60-km topography or latitude/longitude
- 20km land-use, look-up table for roughness length, albedo, emissivity
- software to convert from RUC native coordinates/variables to isobaric coordinates/variables
- 13-km RUC terrain elevation map
- 20-km RUC (pre June05) topography map
- NCEP daily sea-surface temperature file currently used in RUC
- Lightning coverage - Env Canada
Snow/ice data from RUC, NOAA-NESDIS, NOAA-NOHRSC, Environment Canada
Snow cover / depth analyses for comparison with RUC cycled snow cover/water equivalent
- NESDIS daily snow cover and interactive snow cover from NESDIS which can be compared with
- Env Canada snow depth analysis
- NOHRSC-NOAA snow analyses
- RUC snow cover (operational - NCEP) (cycled using RUC land-surface model, updated hourly)
- RUC snow cover (development - ESRL)
Other sites to obtain real-time RUC-based weather graphics
- RUC Meteograms from NCEP/EMC
- NCEP/NCO web page w/RUC fields.
- NCEP/Manikin web page w/ RUC output for convective forecasting.
- Storm Prediction Center Composite Map (CompMap) using RUC data -- can overlay different fields in a Java script
- Comprehensive RUC Graphics from NCAR/RAP/Greg Thompson, including cloud depictions
- Aviation grids of winds, icing, and turbulence using RUC (0-12h) from ADDS at Aviation Weather Center