NOUS41 KWBC 151420



Technical Implementation Notice 16-35

National Weather Service Headquarters Washington DC

1020 AM EDT Thu Sep 15 2016


To:       Subscribers:

          -NOAA Weather Wire Service

          -Emergency Managers Weather Information Network


          Other NWS and NOS partners and NWS and NOS employees


From:     Timothy McClung

          Portfolio Manager

          Office of Science and Technology Integration


Subject:  GPS-PW changes on NCEP servers Effective Sept 27, 2016


This notification is a follow up to Service Change Notice (SCN)

16-19. Earth System Research Laboratory (ESRL)/Global Systems

Division (GSD) currently produces Global Positioning System

(GPS) Precipitable Water (PW) output that is publicly available.

Starting September 30, 2016, GSD will no longer create these

files. Thus, beginning on Tuesday, September 27, 2016, NOAA will

instead begin obtaining the newly restricted data from a private

vender for continued model assimilation. Included within the

NCEP models are the GSD GPW-PW Binary Universal Form for the

Representation (BUFR) dump files:


  Global Forecast System (GFS)

  Global Data Assimilation System (GDAS)


Beginning with the 12z cycle on September 27, the following

changes to the GFS and GDAS can be expected:


- The following files will no longer be available from



    Where YYYYMMDD is Year, Month, Day and CC is cycle


- A new file will be available and only contain international

reports of GPS-PW with name:





If you have any further questions about these changes, please

reference the original SCN 16-19:


If you have any NCEP data questions, contact:


Carissa Klemmer

NCEP Dataflow Team Lead

College Park, MD



National NWS Technical Implementation Notices are available at: