NOUS41 KWBC 091554
PNSWSH

 

Public Information Statement, Comment Request

National Weather Service Headquarters, Washington , DC

1054 AM EST Wed Nov 9 2011

 

To:          Subscribers:

         -Family of Services

         -NOAA Weather Wire Service

         -Emergency Managers Weather Information Network

         -NOAAPORT

               Other NWS Partners, Users and Employees

 

From:         Geoff DiMego

         Chief, Mesoscale Modeling Branch

         NCEP/Environmental Modeling Center

 

Subject: Soliciting Public Comments through December 12, 2011,

         on the removal of some obsolete RUC model output

 

The National Centers for Environmental Prediction (NCEP) will be replacing the Rapid Update Cycle (RUC) model with the Rapid Refresh (RAP) in early 2012.  Please see NWS TIN 11-36 announcing the intent to make this change. Based on NCEP’s current knowledge of RUC user requirements, NCEP is trying to continue providing all pertinent output products from the RAP now produced from the RUC. In the interest of making the best use of resources across the enterprise, NWS is proposing to remove several obsolete RUC products when the transition to the RAP occurs. Details are given below about the products slated for removal. NWS is seeking comments on this proposed change through December 12, 2011.

 

The RUC and subsequent RAP models have a native resolution of 13km.  RUC output is produced on 13, 20, and 40 km output grids that cover the domain slightly larger than the CONUS. The RAP covers a much larger domain; a new 32 km full-domain and 11 km Alaska regional grids will be generated in addition to all of the current grids generated in the RUC with the exceptions listed in the next section. 

 

The products NCEP is proposing to remove are the following:

 

A. 80 km output grids: 80 km grids represent an inferior grid resolution; output is only available for a small fraction of the cycles and forecast hours for which the RUC and RAP are run.  These products are available on NOAAPORT under the WMO headers Y*Q*** KWBG and Z*Q*** KWBG, where the * digits of the header varies depending on the element and time for which the grid is valid.  The 80 km grids are available in aggregated files at the following locations:

 

NWS FTP server: ftp://tgftp.nws.noaa.gov/SL.us008001/ST.opnl/MT.ruc_CY.hh/RD.YYYYMMDD/PT.grid_DF.gr2/fh.xxxx_tl.press_gr.us80km

 

where hh is the model cycle, YYYYMMDD is the date, and xxxx is the forecast projection.

 

NCEP server:

ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/ruc/prod/ruc2a.YYYYMMDD/ruc2.tccz.grb2fxx.grib2

 

where YYYYMMDD is the date, cc the model cycle, and xx the forecast projection.

 

B. Surface "sgrb" files:  These surface files were originally created to contain a small subset of RUC output fields. All of the fields in the sgrb files are available in the 13, 20, and 40 km pgrb files for users to obtain, duplicating output. The sgrb files are currently available in aggregated files at the following locations:

 

NWS FTP server:

 ftp://tgftp.nws.noaa.gov/SL.us008001/ST.opnl/MT.ruc_CY.hh/RD.YYYYMMDD/PT.grid_DF.gr2/

 

where hh is the model cycle and YYYYMMDD is the date.  The filenames are fh.xxxx_tl.press_gr.sgrib for the 40 km grid and fh.xxxx_tl.press_gr.sgrib20 for the 20 km grid, where xxxx is the forecast projection.

 

NCEP server:

ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/ruc/prod/ruc2a.YYYYMMDD

 

where YYYYMMDD is the date.  The filenames are ruc2.tccz.sgrbfxx.grib2 for the 40 km grid and ruc2.tccz.sgrb20fxx.grib2 for the 20 km grid, where cc is the model cycle, and xx the forecast projection.

 

The sgrb files are also available on NCEPs NOMADS system through the grib filter application at:  http://nomads.ncep.noaa.gov/cgi-bin/filter_ruc.pl

 

C. 40 km bgrb output grids containing output on the native levels:  Most users use model output on pressure levels; the RUC/RAP output on native levels will continue to be available at finer resolutions than 40 km. The 40 km "bgrb" files are  available in aggregated files at the following locations:

 

NWS FTP server:

 ftp://tgftp.nws.noaa.gov/SL.us008001/ST.opnl/MT.ruc_CY.hh/RD.YYYYMMDD/PT.grid_DF.gr2/fh.xxxx_tl.press_gr.bgrib

 

where hh is the model cycle, YYYYMMDD is the date, and xxxx is the forecast projection.

 

NCEP server:

 

ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/ruc/prod/ruc2a.YYYYMMDD/ruc2.tccz.bgrbfxx.grib2

 

where YYYYMMDD is the date, cc the model cycle, and xx the forecast projection.

 

NWS will evaluate all comments to determine whether to proceed with this change as part of the RUC to RAP transition. NCEP will issue another TIN if the decision is made to terminate any or all of these products.

 

Send comments on this proposal to:

 

   Geoff Manikin

   NWS/NCEP Environmental Modeling Center

   Camp Springs, MD

   geoffrey.manikin@noaa.gov

 or

 

  Rebecca Cosgrove

  NWS/NCEP Central Operations

  Camp Spring , MD

  rebecca.cosgrove@noaa.gov

 

National Public Information Statements are online at:

 

     http://www.weather.gov/os/notif.htm

 

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