NOUS41 KWBC 141705 AAB



Public Information Statement PNS16-43

National Weather Service Headquarters Washington, DC

105 PM EST Wed Dec 14 2016


To:       Subscribers:

          -NOAA Weather Wire Service

          -Emergency Managers Weather Information Network


          Other NWS Partners, Users and Employees


From:     Arun Chawla

          Chief, Marine Modeling and Analysis Branch


Subject:  Soliciting Public Comments on the Removal of NCEP's

          Great Lakes Wave (GLW) Forecast System NAM-driven

          cycles through January 6, 2017


The National Centers for Environmental Prediction (NCEP) is

proposing to stop running the NAM-driven GLW model cycles 00Z,

06Z, 12Z and 18Z, and to remove all GLW outputs from these

cycles from the NCEP servers. The change will have no effect on

the NDFD-driven GLW cycles (GLWN), run operationally at 03Z,

09Z, 15Z and 21Z.


The NAM-driven GLW runs will be replaced by hourly NDFD-driven

GLWN runs, scheduled to become operational by mid-2017. 


Operational NAM-driven GLW output is distributed via the

following systems:



-  data/nccf/com/wave/prod/glw.YYYYMMDD/

   Where YYYYMMDD is Year, Month, Day

-  Output is available from 00-36hr hourly, 36-60hr every 

   3 hours, and 60-84hr every 6 hours

-  Output is available in grib2 format for the native Lambert

   conformal ~2.5km NDFD grid.


Listed below are the products NCEP is proposing to remove:


1) Bulletins


Text bulletins with partitioned spectral fields at several

Great Lakes buoys provided in tar files, for CYC=00Z, 06Z,

12Z and 18Z as follows:

- glw.tCYCz.bull_tar

- glw.tCYCz.cbull_tar

- glw.tCYCz.csbull_tar


Untarred bulletins in the following directories:

- bulls.t00z/

- bulls.t06z/

- bulls.t12z/

- bulls.t18z/


2) Full spectral outputs at Great Lakes buoys for CYC=00Z, 06Z,

12Z and 18Z in tar files:

- glw.tCYCz.spec_tar.gz


3) Gridded GRIB2 data files, as follows.


Great Lakes NDFD section 2.5km resolution Lambert conformal grid

GRIB2 files with several wave parameters, for CYC=0Z, 06Z, 12Z

and 18Z:

- glw.grlc_2p5km.tCYCz.grib2


Wave steepness grib2 files for CYC=00Z, 06Z, 12Z and 18Z:

- glw.wstp.grlc_2p5km.t00z.grib2


NWS will evaluate all comments to determine whether to proceed

with this change. If approved, the changes will coincide with

the NAM upgrade on or around February 1, 2017. Users can

reference this TIN 16-41 for the exact date these changes will

take place:


Send comments on this proposal to:


   Jose-Henrique Alves

   NWS/NCEP Environmental Modeling Center

   College Park, MD


   Carissa Klemmer

   NWS/NCEP Central Operations

   College Park, MD


National Public Information Statements are online at: