-------- Original Message --------
522
NOUS41 KWBC 161308
PNSWSH
Public Information Notice: Amended
National Weather Service Headquarters Washington DC
907 AM EDT Tue Jul 16 2013
To: Subscribers:
- Family of Services
- NOAA Weather Wire Service
- Emergency Managers Weather Information Network
- NOAAPORT
Other NWS partners and NWS employees
From: Andrew Stern
Acting Chief, Meteorological Services Division
Subject: Amended: Extending Comment Period on Increasing the
Resolution in the National Digital Forecast Database
Until December 31, 2013
Amended to extend the comment period to December 31, 2013
On August 28, 2012, the spatial resolution in the National
Digital Forecast Database (NDFD) was increased, on an
experimental basis, to 2.5km resolution for all forecast times.
In addition, the temporal resolution was made accessible at one
hour resolution for the first 36 hours from NDFD issuance time in
experimental status. These are the finest spatial and temporal
resolutions at which NWS Weather Forecast Offices (WFOs) in the
conterminous United States (CONUS) provide forecasts. Forecasts
from WFOs and NWS National Centers that employ coarser
resolutions are mapped onto the finer resolution NDFD grid.
The increased spatial and temporal resolution applied to files
containing data for the entire CONUS, but not Alaska, Hawaii,
Guam, Puerto Rico, the Virgin Islands, or the 16 CONUS
subsectors. These subsectors remain at their current operational
resolutions.
The NWS will accept comments and feedback on the increase in
resolution during the experimental period through December 31,
2013. Links to surveys are online at:
http://www.weather.gov/survey/NWS-survey.php?code=ndfd-grids25
Pending analysis of comments, the NWS will decide whether or not
to proceed to transition the experimental fine resolution to
operational status for the CONUS. Current operational
resolutions would continue for Alaska, Hawaii, Guam, Puerto Rico,
the Virgin Islands, and the 16 CONUS subsectors.
Specifications for operational and experimental NDFD grids can be
viewed at the following URL:
http://graphical.weather.gov/docs/ndfdSRS.htm
The NDFD continues in parallel in operational phase at current
spatial and temporal resolutions throughout the experimental
period. Experimental fine resolution forecasts are updated
approximately 15 minutes after operational NDFD forecasts. NDFD
graphics and Simple Object Access Protocol/REST/XML services are
provided from operational NDFD grids.
To access experimental fine resolution grids use the following
URLs:
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 are provided in
individual files for each day in order to limit file sizes.
Experimental grids for selected elements are more tightly packed
in GRIB format with both decimal and binary scaling applied.
GRIB 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 GRIB packing for operational NDFD files are
unchanged during the experimental period. Experimental Ice
Accumulation and daily Maximum and Minimum Relative Humidity
grids also remain unchanged.
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
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
1325 East West Highway
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
1325 East West Highway
Silver Spring, Maryland 20910
Andy.Horvitz@xxxxxxxx
Service Change 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
$$