NOUS41 KWBC 011411



Technical Implementation Notice 11-20

National Weather Service Headquarters Washington DC

1011 AM EDT Wed Jun 1 2011


To:       Subscribers:

          -Family of Services

          -NOAA Weather Wire Service

          -Emergency Managers Weather Information Network


          Other NWS partners and NWS employees


From:     Tim Mcclung

          Chief, Science Plans Branch

          Office of Science and Technology


Subject:  Addition of 2.5 km RTMA Products to NOAAPORT


The National Centers for Environmental Prediction (NCEP) is now disseminating new Real Time Mesoscale Analysis (RTMA) products for the contiguous United States (CONUS) on NOAAPORT.  The RTMA is a set of gridded surface analyses and surface analysis uncertainty fields made available at an hourly temporal frequency. The CONUS RTMA was previously only available on NOAAPORT at a horizontal resolution of 5 kilometers (km). These new RTMA products have a horizontal resolution of 2.5 km. 


The grids listed in Table 1 below are available at a resolution of 2.5 km. The GOES effective cloud amount is not available at the 2.5 km resolution and will continue to be provided at a horizontal resolution of 5 km.


The intention is to remove the 5km RTMA products (with the exception of the GOES effective cloud amount) from NOAAPORT and all other distribution methods once sufficient time has passed to allow necessary software upgrades. A separate announcement will be sent prior to removing the 5km products.


Table 1:  CONUS RTMA products available at 2.5 km resolution and their associated WMO headers


WMO Header     RTMA Parameter


LTIA98 KWBR    temperature

LTIA98 KWBR    temperature analysis uncertainty

LRIA98 KWBR    dewpoint temperature

LRIA98 KWBR    dewpoint temperature uncertainty

LNIA98 KWBR    wind speed

LNIA98 KWBR    wind speed analysis uncertainty

LNIA98 KWBR    wind direction

LNIA98 KWBR    wind direction analysis uncertainty

LUIA98 KWBR    u wind component 

LVIA98 KWBR    v wind component 

LEIA98 KWBR    accumulated precipitation

LPIA98 KWBR    surface pressure analysis

LPIA98 KWBR    surface pressure analysis uncertainty

LHIA98 KWBR    model terrain height



The RTMA data for the CONUS is also available from NDGD at:


and on the NCEP server at:



There are three files for each hour located on the NCEP server.  Files with names such as rtma2p5.t00z.2dvaranl_ndfd.grb2 contain all of the RTMA analysis fields and the associated errors, with the exception of precipitation. 


Files with names such as rtma2p5.t00z.2dvarges_ndfd.grb2 contain the first guess fields used by the RTMA.  Files with names such as rtma2p5.t00z.pcpn_ndfd.grb2 contain the precipitation analysis.


NCEP will continue to refine the RTMA.  Users may provide

feedback on the experimental RTMA products at:


For questions regarding the RTMA, please contact:


  Geoff Dimego

  NCEP/Environmental Modeling Branch

  Camp Springs , MD 20746

  301-763-8000 x 7221


For questions regarding the dataflow aspects of these data 
sets please contact: 
  Rebecca Cosgrove
  NCEP/NCO Dataflow Team
  Camp Springs, Maryland 20746
  301-763-8000 X 7198

National Technical Implementation Notices are online at: