NOUS41 KWBC 231822
PNSWSH
Public Information Notice
National Weather Service Headquarters Washington DC
223 PM EDT Thu Aug 23 2012
To:Subscribers:
- Family of Services
- NOAA Weather Wire Service
- Emergency Managers Weather Information Network
- NOAAPORT
Other NWS partners and NWS employees
From:Jason Tuell
Chief, Meteorological Services Division
Subject:Seeking Comments on Increasing the Resolution in the
National Digital Forecast Database (NDFD) Effective
August 28, 2012
Effective Tuesday, August 28, 2012, at 10:00 am EDT, 1400
Coordinated Universal Time (UTC), the NDFD spatial resolution
will become available in experimental status at 2.5km resolution
for all forecast times. The NDFD temporal resolution will be
available in experimental status at 1 hour resolution for the
first 36 hours from NDFD issuance time. These are the finest
spatial and temporal resolutions at which Weather Forecast
Offices in the Conterminous United States (CONUS) provide
forecasts. Forecasts from NWS offices and centers employing
coarser resolutions will be mapped onto the finer resolution
NDFD grid.
This change will affect files which contain data for the entire
CONUS, but will not include Alaska, Hawaii, Guam, Puerto Rico and
the Virgin Islands, or the 16 CONUS subsectors which will remain
at their current operational resolutions.
Specifications for operational and experimental NDFD grids can be
viewed at the following URL:
http://graphical.weather.gov/docs/ndfdSRS.htm
Operational NDFD data will continue to be provided in parallel at
current spatial and temporal resolutions throughout the
experimental 120 day period. Experimental fine resolution
forecasts will be updated approximately 15 minutes after
operational NDFD forecasts.NDFD graphics and SOAP/REST/XML
services will continue to be provided from operational NDFD grids
during the experimental 120 day period.
To access experimental fine resolution grids, go to:
ftp://tgftp.nws.noaa.gov/sl.us008001/st.expr/df.gr2/dc.ndfd/ar.co
nus/
or
http://weather.noaa.gov/pub/sl.us008001/st.expr/df.gr2/dc.ndfd/ar
.conus
Experimental grids for forecast days 1 through 3 will be provided
in individual files for each day to limit file sizes.
Experimental grids for selected elements will be more tightly
packed in GRIB2 format with both decimal and binary scaling
applied.GRIB2 encoding characteristics for each NDFD element
can be viewed at the following URL:
http://graphical.weather.gov/docs/grib_design.html#element_encodi
ng_lo
File structures and GRIB2 packing for operational NDFD files will
remain unchanged during the experimental period. Experimental Ice
Accumulation and daily Maximum and Minimum Relative Humidity
grids will also remain unchanged, i.e., stay at 5km resolution.
WMO headers and file structures for current operational and
experimental NDFD files can be viewed at:
http://www.nws.noaa.gov/ndfd/resources/NDFDelem_current.xls
WMO headers and files structure for the new experimental fine
resolution files can be viewed at:
http://www.nws.noaa.gov/ndfd/resources/NDFDelem_fullres.xls
At the conclusion of the 120 day period, NWS will evaluate any
comments and decide whether to proceed with operational
implementation for the entire CONUS. Current operational
resolutions will continue for Alaska, Hawaii, Guam, Puerto Rico
and the Virgin Islands, and the 16 CONUS subsectors.
The NWS will accept comments and feedback on the increase in
resolution during the experimental period through at least
December 31, 2012.The survey link is online at:
http://www.nws.noaa.gov/survey/nws-survey.php?code=ndfd-grids25
General information on accessing and using NDFD elements is
online at:
http://ndfd.weather.gov/technical.htm
For general questions regarding NDFD data, please email:
nws.ndfd@xxxxxxxx
For technical questions regarding NDFD data, please contact:
David Ruth
Chief, Mesoscale Prediction Branch
NOAA/NWS Office of Science and Technology
Silver Spring, Maryland 20910
David.Ruth@xxxxxxxx
For questions regarding this notice, please contact:
Andy Horvitz
National Weather Service
Office of Climate Water and Weather Services
Silver Spring, Maryland 20910
Andy.Horvitz@xxxxxxxx
Technical Implementation Notices specifically related to NDFD are
online at:
http://www.weather.gov/ndfd/tins.htm
National Public Information Notices are online at:
http://www.weather.gov/os/notif.htm
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