386
NOUS41 KWBC 201110
PNSWSH

Technical Implementation Notice 11-18
National Weather Service Headquarters Washington DC
710 AM EDT Fri May 20 2011

To:      Subscribers:
         - Family of Services
         - NOAA Weather Wire Service
         - Emergency Managers Weather Information Network
         - NOAAPORT
         Other NWS partners, users and NWS employees

From:    Tim McClung
         Science Plans Branch Chief
         Office of Science and Technology

Subject: Change to Experimental Gridded Localized Aviation
         Model Output Statistics Program (LAMP) Products and
         Transition to Operations Effective June 21, 2011

Effective Tuesday, June 21, 2011, beginning with the 1200
Coordinated Universal Time (UTC) run, NWS will change the
experimental Gridded LAMP (GLMP) products for CONUS. The
following changes to the experimental data will occur:

1. Products will include WMO headers in anticipation of the
   transition to operations
2. Products will be encoded with binary scaling to produce
   smaller files
3. Special value to designate "unlimited ceiling height or
   ceiling height" < 12,000 feet will change from the current
   value of -1 to the new value of -100

Effective Tuesday, September 27, 2011, beginning with the 1200
Coordinated Universal Time (UTC) run, NWS will transition the
experimental GLMP products to operational status, at which time
the products will be disseminated on the Satellite Broadcast
Network (SBN), NOAAPORT, and will be available in the
operational National Digital Guidance Database (NDGD).

The Gridded LAMP products contain guidance on a 2.5 km Lambert
Conformal grid covering the same expanse as the National
Digital Forecast Database (NDFD) CONUS grid.  Grids are
generated hourly consisting of gridded forecasts for
projections of 1 to 25 hours in advance as well as gridded
observations for the initial time of the Gridded LAMP cycle.
Grids will be available for the following elements with others
to be added later:

  2-meter temperature observations and the associated error
     estimations
  2-meter dewpoint temperature observations and the associated
     error estimations
  Ceiling height observations
  Visibility observations
  2-meter temperature forecast guidance
  2-meter dewpoint temperature forecast guidance
  Ceiling height forecast guidance
  Visibility forecast guidance

The products are available in GRIB2 format and are currently
available in the experimental NDGD. They are available on the
NWS server at:

ftp://tgftp.nws.noaa.gov/SL.us008001/ST.expr/DF.gr2/DC.ndgd/GT.lmpgfs/AR.conus
 or
http://weather.noaa.gov/pub/SL.us008001/ST.expr/DF.gr2/DC.ndgd/GT.lmpgfs/AR.conus

Beginning September 27, 2011, the products will be available in
GRIB2 format in the operational NDGD, and will no longer be
available in the experimental NDGD.  They will be available on
the NWS server at:

ftp://tgftp.nws.noaa.gov/SL.us008001/ST.opnl/DF.gr2/DC.ndgd/GT.glmp/AR.conus
 or
http://weather.noaa.gov/pub/SL.us008001/ST.opnl/DF.gr2/DC.ndgd/GT.glmp/AR.conus

A web page outlining the Gridded LAMP products and the NWS
server directory and file structure can be found online at:

   http://www.nws.noaa.gov/mdl/gfslamp/docs/glmpinfo.php

The new communication identifiers for the GRIB2 products are
shown below in Tables 1 and 2.  A complete list of GLMP WMO
headings is available at

   http://www.nws.noaa.gov/mdl/gfslamp/docs/glmpheaders.pdf

Table 1:  Communication identifiers for the GLMP gridded
observation products in GRIB2 format.  Listed below are
representations of the WMO headings. xx represents the valid
UTC hour (00-23).

WMO HEADING     ELEMENT
-----------     -------
LAUAxx KMDL     2-meter gridded temperature observations
LAUBxx KMDL     2-meter gridded temperature observation
                error estimations
LBUAxx KMDL     2-meter gridded dewpoint temperature
                observations
LBUBxx KMDL     2-meter gridded dewpoint temperature
                observation error estimations
LCUAxx KMDL     Gridded ceiling height observations
LDUAxx KMDL     Gridded visibility gridded observations

Table 2:  Communication identifiers for the GLMP gridded
forecast products in GRIB2 format. Listed below are
representations of the WMO headings. xx represents the forecast
projection (01-25).

WMO HEADING     ELEMENT
-----------     -------

LKUAxx KMDL     Gridded 2-meter temperature forecasts
LLUAxx KMDL     Gridded 2-meter dewpoint temperature forecasts
LMUAxx KMDL     Gridded ceiling height forecasts
LNUAxx KMDL     Gridded visibility forecasts

If you have technical comments or questions, please contact:

Judy Ghirardelli
National Weather Service
Meteorological Development Laboratory
Judy.Ghirardelli@noaa.gov
301-713-0056 x194

Links to the LAMP products and descriptions can found at:

   http://www.nws.noaa.gov/mdl/gfslamp/gfslamp.shtml

National Public Information Statements are online at:

   http://www.weather.gov/os/notif.htm

$$
NNNN