NOUS41 KWBC 181150

PNSWSH

 

Service Change Notice 17-94

National Weather Service Headquarters Silver Spring, MD

750 AM EDT Fri Aug 18 2017

 

To:        Subscribers:

           -NOAA Weather Wire Service

           -Emergency Managers Weather Information Network

           -NOAAPORT

           Other NWS Partners, Users and Employees

 

From:      Dave Myrick

           NWS Office of Science and Technology Integration

 

Subject:   Update NWM Processing of Streamflow Observations

           Effective August 22, 2017

 

Effective on or about August 22, 2017, beginning with the 1300

Coordinated Universal Time (UTC), the National Centers for

Environmental Prediction (NCEP) will update the National Water

Model (NWM) data pre-processing scripts to address an issue

impacting the model's use of USGS streamflow observations. 

 

Currently, the NWM system only searches in the current day's

directory for streamflow observations to assimilate. With this

change, the model will now ingest observations up to 3 hours

into the previous day (as originally intended).  The change will

increase the accuracy of NWM analysis cycle streamflow near

observation locations, especially within the 00 UTC cycle.

 

Users will see the output changes in the following files on the

NCEP Web services:

 

http://nomads.ncep.noaa.gov/pub/data/nccf/com/nwm/prod/nwm.YYYYM

MDD/

ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/nwm/prod/nwm.YYYYMMDD

www.ftp.ncep.noaa.gov/data/nccf/com/nwm/prod/nwm.YYYYMMDD

Where YYYYMMDD is year, month and day

 

The change only impacts the following channel-type output files

(other file types remaining unchanged):

  analysis_assim/*channel_rt*conus.nc

  short_range/*channel_rt*conus.nc

  medium_range/*channel_rt*conus.nc

  long_range_mem*/*channel_rt*conus.nc

 

Questions, comments or requests regarding this change should be

directed to the contacts below.  We will review any feedback and

decide whether to proceed.

 

For questions regarding these changes, please contact:

 

     Brian Cosgrove

     OWP/Analysis and Prediction Division

     Silver Spring, MD

     brian.cosgrove@noaa.gov

or

     Carissa Klemmer

     NWS/NCEP Central Operations

     Dataflow Team Lead

     College Park, MD

     ncep.list.pmb-dataflow@noaa.gov

 

NWS Service Change Notices are online at:

 

   http://www.nws.noaa.gov/om/notif.htm

 

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