NOUS41 KWBC 191446



Technical Implementation Notice 13-18

National Weather Service Headquarters, Washington, DC

1045 AM EDT Fri Jul 19 2013


To:          Subscribers:

             -Family of Services

             -NOAA Weather Wire Service

             -Emergency Managers Weather Information Network


             Other NWS Partners, Users and Employees


From:        Tim McClung

             Science Plans Branch Chief

             Office of Science and Technology


Subject:     Addition of Satellite Observations to Global Data

             Assimilation System Effective August 20, 2013


Effective Tuesday, August 20, 2013, with the 1200 Universal

Coordinated Time (UTC) cycle, the National Centers for

Environmental Prediction (NCEP) will begin incorporating

additional satellite data in the Global Data Assimilation System

(GDAS). These data are necessary to keep up with the evolving

observing system. This change does not alter the format or

content of any output from the GDAS.


The additional observations to be included are the NPP CrIS data,

METOP-B AMSU-A/MHS/GRAS data, and SEVIRI data from Meteosat-10. 

All data should provide some additional information to the

assimilation system, but experiments to date have not shown any

significant positive or negative forecast impact. 


In addition to the potential additional information in the data,

the observations are being added to increase the resiliency to

potential future loss and evolution of the observing system. The

NPP CrIS data supplies similar information and is in a similar

orbit to the Aqua AIRS data.  The METOP-B data is being

incorporated since the METOP-B satellite is replacing the METOP-A

satellite as the primary morning satellite.  SEVIRI data from

Meteosat-10 replaces data from Meteosat-9.  


If you have questions about this change, please contact:


   John Derber

   NWS/NCEP Environmental Modeling Center

   College Park, MD


National Public Information Statements are online at: