[nws-changes] 20121115 amended chgs and additions to NAM-DNG :: Fwd: ADMIN NOTICE NOUS41 KWBC

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-------- Original Message --------

057
NOUS41 KWBC 152114
PNSWSH
Technical Implementation Notice 11-35, Amended 
National Weather Service Headquarters Washington DC
415 PM EST Thu Nov 15 2012
To: Subscribers: 
          -Family of Services
          -NOAA Weather Wire Service
          -Emergency Managers Weather Information Network
          -NOAAPORT
          Other NWS partners and NWS employees
From: Tim McClung 
          Chief, Science Plans Branch
          Office of Science and Technology
Subject: Amended Changes and Additions to NAM-DNG Products, 
          Including Distribution of New High-Resolution DNG
          Effective Date of NOAAPORT Activation: December 4,
          2012.
Amended to set the implementation date to add these products to 
NOAAPORT to Tuesday, December 4, 2012.

The modifications to the current NAM DNG, as part of the upgrade
of the NAM prediction system, were implemented when the NAM
upgrade was completed on October 18, 2011. This amended TIN
covers the addition of these products to NOAAPORT.  No changes
are being made at this time to the content of the products.
Much of what follows is directly from the original phrasing of
TIN 11-35, with some minor wording changes.
Effective with the upgrade of the North American Mesoscale (NAM) 
prediction system, and inclusion of high resolution nests (see
TIN 11-16), the National Centers for Environmental Prediction
(NCEP) will modify and enhance the suite of NAM Downscaled
Numerical Guidance (NAM-DNG).
The current NAM-DNG products are distributed to the Continental 
U.S. (CONUS), Alaska, Hawaii and Puerto Rico out to 84 hours
over the AWIPS SBN/NOAAPORT and are available on the NCEP
server. The new NAM nests are run only to 60 hours but are run
at resolutions much closer to the National Digital Forecast
Database (NDFD) forecast grids used in the DNG than the 12km
NAM, now called the parent grid.
After the modification of existing NAM-DNG is implemented, as 
stated in TIN 11-16, the first 60 hours (54 hours) of the
current 0000 and 1200 UTC (0600 and 1800 UTC), NAM-DNG will come
from the NAM nests instead of from the 12km NAM parent.
--CONUS: 4km NAM nest will feed 5km NAM-DNG 
--Alaska: 6km NAM nest will feed 5.9km NAM-DNG
--Hawaii, Puerto Rico: 3km NAM nests will feed 2.5km NAM-DNG
In this way, only slight downscaling (or upscaling in the case 
of CONUS) is required. Currently, all systems downscale from
12km.
After the change, there may be some unavoidable amount of 
discontinuity between the NAM-nest-based 60-hr (54 hr for 0600
and 1800 UTC) and the NAM-parent-based 63-hr (57 hr for 0600 and
1800 UTC) guidance. These modifications will occur when the NAM
upgrade, detailed in TIN 11-16 linked below, is implemented
later this summer.
www.weather.gov/os/notification/tin11-16nam_changes_aad.htm The enhancement of NAM-DNG will come from the addition of 
NAM-DNG for CONUS and Alaska at double the present NDFD
resolution through the 60 hours covered by the NAM nests.
For CONUS, the 4km NAM nest will feed a 2.5km NAM-DNG. For 
Alaska, the 6km NAM nest will feed a 3km NAM-DNG. Output will be
made available every 3 hours from 0-60 hours for all 4 NAM
cycles.
These new high-resolution NAM-DNG products will be available 
on the NCEP server when the NAM upgrade is implemented. In
addition, simulated composite reflectivity will be added to
output for both the modified and enhanced NAM-DNG. The new high-
resolution NAM-DNG products will be made available on NOAAPORT
on Tuesday December 4, 2012.
The grids listed below in Table 1 for CONUS and Table 2 for 
Alaska will be available at double NDFD resolutions.
NCEP will remove the coarser 5km CONUS and 5.9km Alaska NAM-DNG 
products from NOAAPORT and all other distribution methods once
sufficient time has passed to allow software upgrades.  A
separate announcement will be sent before removing these
products.
Table 1: NAM-DNG products available over CONUS at 
2.5km resolution and their associated WMO headers
WMO Header NAM-DNG Parameter 
[L|M]AJ*** KWBE  Dewpoint temperature
[L|M]AJ*** KWBE  Cloud Cover
[L|M]AJ*** KWBE  Wind Speed
[L|M]AJ*** KWBE  Wind Direction
[L|M]AJ*** KWBE  Wind Gust Speed
[L|M]DJ*** KWBE  Probability of Precipitation (3, 6 & 12 hourly)
[L|M]EJ*** KWBE  Total Precipitation (3, 6 & 12 hourly)
[L|M]HJ*** KWBE  Boundary layer height or wet bulb zero height
[L|M]KJ*** KWBE  Visibility
[L|M]RJ*** KWBE  Minimum/Maximum relative humidity(3 & 12
hourly)
[L|M]SJ*** KWBE  Snow depth (3 & 6 hourly)
[L|M]TJ*** KWBE  Temperature
[L|M]TJ*** KWBE  Minimum/Maximum temperature (3 & 12 hourly)
[L|M]UJ*** KWBE  U component of wind
[L|M]VJ*** KWBE  V component of wind
[L|M]ZJ*** KWBE  Simulated composite reflectivity
Table 2: NAM-DNG products available over Alaska at 3km 
resolution and their associated WMO headers
WMO Header NAM-DNG Parameter 
[L|M]AK*** KWBE  Dewpoint temperature
[L|M]AK*** KWBE  Cloud Cover
[L|M]AK*** KWBE  Wind Speed
[L|M]AK*** KWBE  Wind Direction
[L|M]AK*** KWBE  Wind Gust Speed
[L|M]DK*** KWBE  Probability of Precipitation (3, 6 & 12 hourly)
[L|M]EK*** KWBE  Total Precipitation (3, 6 & 12 hourly)
[L|M]HK*** KWBE  Boundary layer height or wet bulb zero height
[L|M]KK*** KWBE  Visibility
[L|M]RK*** KWBE  Minimum/Maximum relative humidity(3 & 12
hourly)
[L|M]SK*** KWBE  Snow depth (3 & 6 hourly)
[L|M]TK*** KWBE  Temperature
[L|M]TK*** KWBE  Minimum/Maximum temperature (3 and 12 hourly)
[L|M]UK*** KWBE  U component of wind
[L|M]VK*** KWBE  V component of wind
[L|M]ZK*** KWBE  simulated composite reflectivity
A Website outlining all of the NAM-DNG WMO headers is online at: www.nco.ncep.noaa.gov/pmb/changes/nam_dng_wmoheaders.shtml The NAM-DNG grids are made available from the NCEP server at: ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/nam/prod/ 

or

http://www.ftp.ncep.noaa.gov/data/nccf/com/nam/prod
There are files for the four nests: smartconus, smartak, smarthi 
and smartpr followed by the two-digit forecast hour.  The CONUS
files will be named smartconus for the 5km and smartconus2p5 for
the 2.5km.  Similarly Alaska files will be smartak for the 6km
grids and smartak3 for the 3km grids.
For questions regarding the NAM-DNG, please contact: Geoff DiMego 
  NCEP/Environmental Modeling Center
  College Park, Maryland
  301-683-3764
  geoff.dimego@xxxxxxxx
or
  Geoff Manikin
  NCEP/Environmental Modeling Center
  College Park, Maryland
  301-683-3695
  geoffrey.manikin@xxxxxxxx
For questions regarding the dataflow aspects of these data 
sets please contact:
Rebecca Cosgrove 
  NCEP/NCO Dataflow Team
  College Park, Maryland
  301-683-0567
  ncep.list.pmb-dataflow@xxxxxxxx
National Technical Implementation Notices are online at: http://www.weather.gov/os/notif.htm $$
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