NOUS41 KWBC 181130

PNSWSH

 

Service Change Notice 17-101

National Weather Service Headquarters Silver Spring, MD

730 AM EDT Mon Sep 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:  Changes to LAMP station-based and gridded guidance

          effective November 2, 2017

 

On or about Thursday, November 2, 2017, beginning with the 1230

Coordinated Universal Time (UTC) model run, the NWS

Meteorological Development Laboratory (MDL) will implement

changes to the Localized Aviation Model Output Statistics

Program (LAMP) station-based and Gridded LAMP (GLMP) guidance.

 

LAMP station-based guidance is produced at more than 1600

stations in the Continental United State (CONUS), Alaska, Hawaii

and Puerto Rico. GLMP guidance is generated on a 2.5-km Lambert

Conformal grid over the CONUS. LAMP station-based forecasts and

GLMP gridded observations and gridded forecasts (1 to 25 hour

projections) are produced hourly. These products are

disseminated on the Satellite Broadcast Network (SBN),

NOAAPORT, and are available in the operational National Digital

Guidance Database (NDGD).

 

Specific changes are as follows:

 

1. Addition of 1-h convection and lightning gridded guidance

over the CONUS. This new guidance incorporates High Resolution

Rapid Refresh (HRRR) model data, Multi-Radar Multi-Sensor data,

and total lightning data. The following elements will be

available on the 2.5-km National Digital Forecast Database

(NDFD) CONUS grid in GRIB2 format for hourly projections through

25 hours:

 

  1. 1-h Probability of convection

  2. 1-h Potential of convection occurrence (No/Low/Medium/High)

  3. 1-h Probability of lightning

  4. 1-h Potential of lightning occurrence (No/Low/Medium/High)  

 

These elements will be disseminated over the SBN, NOAAPORT and

will be available in NDGD on the NWS ftp server. WMO headers and

NDGD file names for the 1-h convection and lightning products

are listed in Tables 3 and 4 below, respectively. 

 

Comparison images for operational 2-h guidance and experimental

1-h guidance can be viewed at the following links:

 

Convection: http://www.nws.noaa.gov/mdl/lamp/cnv1h_proposed.php

Lightning: http://www.nws.noaa.gov/mdl/lamp/ltg1h_proposed.php

 

The new 1-h convection and lightning gridded guidance will

eventually replace the operational 2-h gridded guidance. 

Dissemination of the operational 2-h gridded guidance will

continue until the 1-h gridded products are available in AWIPS.

 

2. Replacement of 2-h convection and lightning guidance with 1-h

guidance in the LAMP text bulletins (AWIPS PIL "LAV"). The

format of the LAV text bulletins will change as follows:

 

   - Line for 2-h lightning probability (labeled "LP2") will be

     replaced with 1-h lightning probability (labeled "LP1"),

     with probabilities specified for each hour through 25

     hours.

   - Line for 2-h lightning potential (labeled "LC2") will be

     replaced with 1-h lightning potential (labeled "LC1"),

     with potential categories (N/L/M/H) specified for each hour

     through 25 hours.

   - Line for 2-h convection probability (labeled "CP2") will

     be replaced with 1-h convection probability (labeled

     "CP1"), with probabilities specified for each hour through

25    hours.

   - Line for 2-h convection potential (labeled "CC2") will be

     replaced with 1-h convection potential (labeled "CC1"),

     with potential categories (N/L/M/H) specified for each hour

     through 25 hours.  

 

There will be no changes to the LAMP BUFR message for convection

and lightning. The 2-h lightning guidance will remain in the

BUFR message until such time as AWIPS decoders are modified to

handle the 1-h guidance. At that time, the 1-hr lightning

guidance will replace the 2-hr lightning guidance and the 1-hr

convection guidance will be added in the BUFR.

 

Example text bulletins containing the new 1-h convection and

lightning guidance can be viewed at the following link:

 

https://sats.nws.noaa.gov/~lamp/exprlamp/bull/cy.latest.txt

 

3. Addition of 332 new stations to the LAMP text bulletins and

BUFR files to match the stations available in the GFS MOS (MAV)

text bulletins. Added stations will have guidance for ceiling

height, visibility, obstruction to vision, 1-h convection

probability and potential, and 1-h lightning probability and

potential.  Guidance for other elements will be added in future

implementations.

 

A list of stations being added to the LAMP text bulletins and

BUFR messages is provided at the following link:

 

https://www.weather.gov/mdl/lamp_newsites_v2.1.0

 

New stations are not being added to the GLMP analysis at this

time.  These sites will be added to GLMP with a future

implementation.

 

4. Use the most recent METAR and special (SPECI) observations as

predictors for all elements, in place of the traditional top-of-

the-hour observation. This approach leverages the most recent

observations that are available at the time of the LAMP run,

which benefits the station LAMP forecasts and the grids that use

the station forecasts, especially in the first few hours. 

 

5. Addition of station-based and GLMP guidance for ceiling and

visibility produced every 15 minutes using the most recent METAR

and SPECI observations.  In addition to the "base" LAMP run

which runs at 30 minutes past the hour out to 25 hours, guidance

for ceiling, visibility, and obstruction to vision will be

produced 3 additional times per hour at nominal runs times of

00, 15, and 45 minutes past each hour, for hourly projections

out to 3 hours. Forecasts from the 15-minute runs out to 3 hours

will still be valid at the top of the hour.

 

Prototype text bulletins containing ceiling and visibility

guidance out to 3 hours generated every 15 minutes can be viewed

at the following link:

 

https://sats.nws.noaa.gov/~lamp/exprlamp/bull/cyupdate.latest.txt

 

Note that the above link will show full bulletins if the most

recent LAMP run was the "base" LAMP run that ran nominally at 

30 past the hour. Prototype GLMP images for ceiling and

visibility out to 3 hours generated every 15 minutes can be

viewed at the following link:

 

https://sats.nws.noaa.gov/~glmp/glmp_expr_v2.1.0.php

 

At this time, the text bulletins and gridded output generated

from the 15-minute (non-base) LAMP runs will not be disseminated

over the SBN/NOAAPORT due to issues with AWIPS compatibility.

Instead this guidance will be experimentally available on a web

page for user evaluation at the links provided above. The 

15-minute guidance may be added to the SBN in a future

implementation once AWIPS is able to ingest the 15-minute data. 

 

Benefits of the system changes include:

 

  1. Improved spatial and temporal resolution of convection and

     lightning guidance over the CONUS.

  2. Availability of guidance for additional stations to match

     what is available in the GFS MOS text bulletins.

  3. Infusing most recent METAR and SPECI observations into the

     LAMP system results in improved skill primarily in the

     first few hours.

  4. Additional 15-minute (non-base) runs for ceiling and

     visibility leverage most recent METAR and SPECI

     observations, resulting in improved forecast skill for

     these elements through 3 hours.

 

More details about LAMP/GLMP products and this implementation

can be found online at the LAMP Documentation web site:

 

http://www.weather.gov/mdl/lamp_docs

 

Changes to Dissemination:

 

   1. The new 1-h convection and lightning gridded guidance in

      GRIB2 format will be added to the SBN/NOAAPORT and

      operational NDGD.

   2. The 2-h lightning products at 5 km resolution over the

      CONUS will be removed from the SBN/NOAAPORT. A list of

      headers being removed is provided in Table 5 below. Since

      the 2-h products are available in AWIPS at 2.5 km

      resolution, it is no longer necessary to disseminate the

      legacy 5 km guidance.  This removal notification was

      provided in TIN 13-50:

 

http://www.nws.noaa.gov/os/notification/tin13-50lamp_cnvltgaab.htm

 

There are no other changes to the dissemination with this

implementation. The LAMP and GLMP products will continue to be

available in operational NDGD, SBN, NOAAPORT and NWS ftp server.

 

Details for the locations of the LAMP and GLMP products on the

NWS ftp server can be found here:

 

http://www.weather.gov/mdl/lamp_NWS_tgftp_server

 

Complete lists of LAMP and GLMP WMO headers can be found here:

 

LAMP headers:

http://www.weather.gov/media/mdl/lampheaders_vert_structure_v2.1.0_05192017.pdf

 

GLMP headers:

http://www.weather.gov/media/mdl/glmpheaders_2016.pdf

 

The communication identifiers for the LAMP text and BUFR

products are shown in Tables 1 and 2 below.

 

Table 1: Communication identifiers for the GFS-based LAMP

products in ASCII format. Listed below are the WMO heading and

the AWIPS identifier.

 

WMO heading     AWIPS ID

-----------     --------

FOUS11 KWNO     LAVUSA

 

Table 2: Communication identifiers for the GFS-based LAMP

products in BUFR format.  Listed below are the WMO headings.

 

WMO heading     Region

-----------     ------

JSMF10 KWNO     LAMP BUFR Pacific Region

JSMF11 KWNO     LAMP BUFR Northeast Region

JSMF12 KWNO     LAMP BUFR Southeast Region

JSMF13 KWNO     LAMP BUFR North Central Region

JSMF14 KWNO     LAMP BUFR South Central Region

JSMF15 KWNO     LAMP BUFR Rocky Mountains Region

JSMF16 KWNO     LAMP BUFR West Coast Region

JSMF17 KWNO     LAMP BUFR Alaska Region

 

Table 3:  Communication identifiers for the 1-h convection and

lightning gridded products in GRIB2 format. Listed below are

representations of the WMO headers where xxx represents the

valid day and valid UTC hour of the forecasts.  Please see

updated LAMP header document linked above for further details.

 

WMO HEADER      ELEMENT

-----------     -------

YGUxxx KWNO     Gridded 1-h lightning probability

YHUxxx KWNO     Gridded 1-h lightning potential of occurrence

YIUxxx KWNO     Gridded 1-h convection probability

YJUxxx KWNO     Gridded 1-h convection potential of occurrence

 

Table 4:  NDGD file names for 1-h convection and lightning

products in GRIB2 format.

 

NDGD FILENAME    ELEMENT

-------------    -------

ds.plt01.bin     Gridded 1-h lightning probability

ds.olt01.bin     Gridded 1-h lightning potential of occurrence

ds.pcv01.bin     Gridded 1-h convection probability

ds.ocv01.bin     Gridded 1-h convection potential of occurrence

 

Table 5:  Communication identifiers for the 2-h lightning

gridded products at 5 km resolution that will be removed from

the SBN/NOAAPORT.  Listed below are representations of the WMO

headers where xxx represents the valid day and valid UTC hour of

the forecasts.

 

WMO HEADER      ELEMENT

-----------     -------

LAUxxx KWNO     Gridded 2-h lightning probability (5 km)

LBUxxx KWNO     Gridded 2-h lightning potential (5 km)

 

A consistent parallel feed of data will be made available in

the near future on the NCEP HTTP site.  The data will be

available at the following URLs:

 

http://para.nomads.ncep.noaa.gov/pub/data/nccf/noaaport/lmp

 

http://para.nomads.ncep.noaa.gov/pub/data/nccf/noaaport/glmp

 

Questions, comments or requests regarding this change should be

directed to the contact below.  We will review feedback and

decide whether to proceed.

 

  Judy Ghirardelli

  National Weather Service

  Meteorological Development Laboratory

  Judy.Ghirardelli@noaa.gov

  301-427-9496

 

Links to the LAMP products and descriptions can be found at:

 

    http://www.weather.gov/mdl/lamp_home

 

National Service Change Notices are online at:

 

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

 

NNNN