NOUS41 KWBC 291830



Technical Implementation Notice 12-40

National Weather Service Headquarters, Washington, DC

230 PM EDT Wed Aug 29 2012


To:          Subscribers:

             -Family of Services

             -NOAA Weather Wire Service

             -Emergency Managers Weather Information Network


             Other NWS Partners, Users and Employees


From:        Geoff DiMego

             Chief, Mesoscale Modeling Branch

             NCEP/Environmental Modeling Center


Subject:     Termination of NCEP’s Rapid Update Cycle Surface

             Analysis System: Effective October 02, 2012


Effective Tuesday, October 2, 2012, with the 1200 Universal

Coordinated Time (UTC) cycle, the National Centers for

Environmental Prediction (NCEP) will stop running the legacy analysis system known as Rapid Update Cycle Surface (RUCS), also known as the RUC Surface Assimilation System (RSAS), and discontinue all output products from this system.


A Public Information Statement was issued on June 28, 2012,

requesting comments on the proposed termination of the RUCS.


Based on responses received, NWS will terminate RUCS and all associated output products on October 2.


The RUCS analysis uses optimum interpolation in 2-dimensions to update its hourly products, resulting in output products on multiple grids. As outlined in the PNS referenced above, similar analyses of surface parameters using the state-of-the-art Gridpoint Statistical Interpolation (GSI) analysis scheme are available from the 12 km North American Mesoscale (NAM) model and its higher resolution nests, the 13 km Rapid Refresh (RAP), and the various domains covered by 2.5 km-5 km Real Time Mesoscale Analysis (RTMA).


The RUCS output is disseminated via the NWS and NCEP FTP servers. No RUCS products are sent on NOAAPORT. Details about the exact RUCS products that will be removed can be found at


More information about the NAM, RAP and RTMA products that are

available as replacements can be found at


If you have questions about this termination, please contact:


   Geoff DiMego

   NWS/NCEP Environmental Modeling Center

   College Park, MD


   Rebecca Cosgrove

   NWS/NCEP Central Operations

   College Park, MD


National Public Information Statements are online at: