NOUS41 KWBC 291830
Technical Implementation Notice 12-40
National Weather Service Headquarters, Washington, DC
230 PM EDT Wed Aug 29 2012
-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:
NWS/NCEP Environmental Modeling Center
College Park, MD
NWS/NCEP Central Operations
College Park, MD
National Public Information Statements are online at: