NOUS41 KWBC 231212

PNSWSH

 

Technical Implementation Notice 13-49

National Weather Service Headquarters Washington DC

712 AM EDT Mon Dec 23 2013

 

To:       Subscribers:

          -Family of Services

          -NOAA Weather Wire Service

          -Emergency Managers Weather Information Network

          -NOAAPORT

          Other NWS Partners, Users and Employees

 

From:     Tim McClung

          Science Plans Branch Chief

          Office of Science and Technology

 

Subject:  Addition of New Elements to Experimental GFS-based

          Gridded MOS Guidance over the CONUS and Alaska. 

 

On or about Tuesday, February 18, 2014, beginning with the 1200

Universal Coordinated Time (UTC) model run, the NWS

Meteorological Development Laboratory (MDL) will add several new

elements to the experimental Global Forecast System (GFS)-based

Gridded Model Output Statistics (MOS) guidance over the CONUS and

Alaska.  The elements to be added include:

 

-Conditional probability of freezing precipitation

-Conditional probability of frozen precipitation

-Conditional probability of liquid precipitation

-Precipitation type conditional best category

-Precipitation potential index (PPI)

-Probability of precipitation occurrence (PoPO)

-Predominant weather

 

Grids for conditional precipitation type probability and best

category are seasonal and will be available from September 1-

May 31 over the CONUS and September 1-June 15 over Alaska. 

Grids for PPI, PoPO, and predominant weather will be available

year round.  Graphics, links to GRIB2 data for download, and more

details on these new GFS-based gridded MOS elements over the

CONUS and Alaska can be found at the following links:

   

http://www.mdl.nws.noaa.gov/~mos/gmos/ptype_conus2p5/

 

http://www.mdl.nws.noaa.gov/~mos/gmos/ptype_alaska/

 

http://www.mdl.nws.noaa.gov/~wxgrid/

 

On the change date, these products will be disseminated on the

Satellite Broadcast Network (SBN), NOAAPORT, and the NWS ftp

server in GRIB2 format. These additional MOS grids will be

produced on a 2.5-km Lambert Conformal grid over the CONUS and on

a 3-km Polar Stereographic grid over Alaska, each grid covering

the same expanse as its respective National Digital Forecast

Database (NDFD) grids. Guidance will be generated from the 0000

and 1200 UTC model cycles for projections every 3 hours from 6 to

192 hours in advance. 

 

The new GRIB2 products for the CONUS will be available in the

experimental area of the National Digital Guidance Database

(NDGD) on the NWS ftp server:

 

ftp://tgftp.nws.noaa.gov/SL.us008001/ST.expr/DF.gr2/DC.ndgd/GT.mosgfs/AR.conus/

 

The new GRIB2 products for Alaska will be available in the

experimental area of NDGD on the NWS ftp server:

 

ftp://tgftp.nws.noaa.gov/SL.us008001/ST.expr/DF.gr2/DC.ndgd/GT.mosgfs/AR.alaska/

 

Each element-specific GRIB2 file will contain a superheader and

individual headers for each forecast projection.  A list of GRIB2

file names for each new gridded MOS element is given in Table 1

below.  Representations of the WMO superheaders for the new CONUS

and Alaska gridded MOS elements are given in Tables 2 and 3,

respectively.

 

Table 1: GRIB2 file names for each new GFS-based Gridded MOS

element:

 

   FILE NAME       ELEMENT

 

   ds.cpoz.bin     Conditional probability of freezing

   ds.cpos.bin     Conditional probability of frozen

   ds.cpor.bin     Conditional probability of liquid

   ds.ptype.bin    Precipitation type best category

   ds.ppi.bin      Precipitation potential index

   ds.popo.bin     Probability of precip. occurrence

   ds.wx.bin       Predominant weather

    

 

Table 2: WMO superheaders for each new 2.5-km CONUS gridded MOS

element.  Listed below are representations of the superheaders

for each element, where ii=98 for short-range guidance (days 1-3)

and ii=97 for medium range guidance (days 4-7):

 

   WMO HEADER     ELEMENT

 

   MAUZii KWBQ    Conditional probability of freezing

   MBUZii KWBQ    Conditional probability of frozen

   MCUZii KWBQ    Conditional probability of liquid

   YLUZii KWBQ    Precipitation type best category

   YMUZii KWBQ    Precipitation potential index

   YNUZii KWBQ    Probability of precip. occurrence

   YZUZii KWBQ    Predominant weather

  

Table 3: WMO superheaders for each new 3-km Alaska gridded MOS

element.  Listed below are representations of the superheaders

for each element, where ii=98 for short-range guidance (days 1-3)

and ii=97 for medium range guidance (days 4-7):

 

   WMO HEADER     ELEMENT

 

   MARZii KWBQ    Conditional probability of freezing

   MBRZii KWBQ    Conditional probability of frozen

   MCRZii KWBQ    Conditional probability of liquid

   LLRZii KWBQ    Precipitation type best category

   LMRZii KWBQ    Precipitation potential index

   LNRZii KWBQ    Probability of precip. occurrence

   LZRZii KWBQ    Predominant weather

 

 

A complete list of the WMO superheaders and individual headers

for the CONUS is available at:

 

  www.nws.noaa.gov/mdl/synop/gmos/gmos2p5headers.pdf

 

A complete list of the WMO superheaders and individual headers

for Alaska is available at:

 

  www.nws.noaa.gov/mdl/synop/gmos/gmosAKheaders.pdf

 

A Web page outlining the gridded MOS guidance and the FTP server

structure can be found at:

 

  http://www.nws.noaa.gov/mdl/synop/gmos.php

 

For questions regarding the addition of precipitation type to

the Gridded MOS suite over the CONUS and Alaska, contact:

 

  Phil Shafer

  NWS Meteorological Development Laboratory

  301 713-0023 x113

  Phil.Shafer@noaa.gov

 

For questions on the addition of predominant weather and PPI

to the Gridded MOS suite over the CONUS and Alaska, contact:

 

  Tabitha Huntemann

  NWS Meteorological Development Laboratory

  301 713-0224 x119

  Tabitha.Huntemann@noaa.gov

 

Links to the MOS products and descriptions are online at:

 

  http://www.nws.noaa.gov/mdl/synop

 

NWS national TINs are online at:

 

  http://www.weather.gov/os/notif.htm

 

$$