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NOUS41 KWBC 312054
PNSWSH

Technical Implementation Notice 15-34, Amended
National Weather Service Headquarters Washington DC
0455 PM EDT Mon Aug 31 2015

To:       Subscribers:
          -Family of Services
          -NOAA Weather Wire Service
          -Emergency Managers Weather Information Network
          -NOAAPORT
          Other NWS Partners, Users and Employees

From:     Tim McClung
          Chief Operating Officer
          Office of Science and Technology Integration

Subject:  Amended: Changes to GFS-based Model Output Statistics
          (MOS)Guidance effective October 1, 2015

Amended to change the implementation date from Tuesday, September
15, 2015, to Thursday, October 1, 2015.

Users may find parallel data for download on NOAA`s Operational
Model Archive and Distribution System (NOMADS) at the following
link (files will reside in gfsmos.YYYYMMDD):

http://para.nomads.ncep.noaa.gov/pub/data/nccf/com/gfs/para/

On or about Thursday, October 1, 2015, beginning with the
1200 Coordinated Universal Time (UTC) model run, the NWS
Meteorological Development Laboratory (MDL) will implement
changes to the Global Forecast System (GFS)-based Model Output
Statistics (MOS) guidance. The changes will include:

1.  Add gridded MOS guidance for CONUS and Alaska for the
Day 8-11 period. Guidance will be available for the following
elements:

1) 2-meter temperature (every 6 h)
2) 2-meter dew point temperature (every 6 h)
3) Daytime maximum temperature
4) Nighttime minimum temperature
5) Relative humidity (every 6 h)
6) Wind speed (every 6 h)
7) Wind direction (every 6 h)
8) 12-h probability of precipitation (every 12 h)

These day 8-11 products will be produced on a 2.5-km Lambert
Conformal grid over the CONUS and 3-km Polar Stereographic grid
over Alaska.  Guidance will be available for the 0000 and
1200 UTC model cycles for projections out to 11 days in advance.
These Day 8-11 Gridded MOS products will be disseminated on the
Satellite Broadcast Network (SBN), NOAAPORT, and the NWS FTP
server in GRIB2 format. Users can view Gridded MOS guidance for
the expanded CONUS domain at the following link (this page is not
operationally supported and guidance may not be current):

http://www.mdl.nws.noaa.gov/~mos/gmos/conus25_all/view_gmos.php

The day 8-11 products for the CONUS and Alaska will be available
in GRIB2 format in the experimental area of the National Digital
Guidance Database (NDGD) on the NWS ftp server at:

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

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

Each element-specific GRIB2 file will reside in the VP.008-450
directory and contain a WMO super header and individual headers.
A listing of the GRIB2 file names for each element is given in
Table 1 below.  Tables 2 and 3 list WMO super headers for CONUS
and Alaska Day 8-11 gridded MOS elements.

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

2.  This change will expand the output mask for the 2.5-km CONUS
grid northward from its current National Digital Forecast
Database (NDFD) extent to include all of the Northwest River
Forecast Center basin and a buffer of 170 km elsewhere along the
border with Canada. This change will affect the following 2.5-km
CONUS Gridded MOS elements:

1) 2-meter temperature
2) 2-meter dew point temperature
3) Daytime maximum temperature
4) Nighttime minimum temperature
5) Wind speed, wind direction, wind gust
6) 6-h/12-h probability of precipitation
7) 6-h/12-h quantitative precipitation amount
8) Relative humidity
9) Total sky cover
10) 24-h snowfall amount

The northward expansion of the 2.5-km CONUS grid will result in a
small increase in GRIB2 file sizes (generally less than 10
percent) for the above listed elements. Grids of 24-h snowfall
amount will be clipped to their current extent and contain
missing values elsewhere. Other elements not listed above will
not be affected by the grid expansion. WMO super headers for the
2.5-km CONUS Gridded MOS elements affected by this change are
listed in Table 4 below. The operational 5-km CONUS Gridded MOS
products will remain on their current NDFD extent and will not be
affected by the expansion of the 2.5-km CONUS grids.

3.  NWS will add new stations to the GFS-based short-range and
extended-range Cooperative Observer Program (COOP) maximum and
minimum temperature messages, known by their AWIPS IDs MCG and
MCX, respectively.  Communication identifiers for affected
products are listed in Table 5 below. A list of the stations
being added can be found at:

http://www.nws.noaa.gov/mdl/synop/gfsmos_changes/newsitesSept2015
.php

4.  NWS will remove stations from the GFS-based short-range and
extended-range COOP maximum and minimum temperature messages,
known by their AWIPS IDs MCG and MCX, respectively. These are
stations that have closed, stopped reporting, or do not contain
sufficient cases to develop MOS equations. Communication
identifiers for the affected products are listed in Table 5
below. A list of the stations being removed can be found at:

http://www.nws.noaa.gov/mdl/synop/gfsmos_changes/droppedsitesSept
2015.php

5.  NWS will remove stations from the GFS-based River Forecast
Center maximum and minimum temperature SHEF message with AWIPS ID
FTP. These are stations that have closed, stopped reporting, or
do not contain sufficient cases to develop MOS equations.
Communication identifiers for the affected products are listed in
Table 6 below. Stations being removed can be found at:

http://www.nws.noaa.gov/mdl/synop/gfsmos_changes/droppedsitesSept
2015.php

6.  This change provides updated thunderstorm guidance for Alaska
valid for the warm season, May through September. NWS has updated
guidance for the probability of a thunderstorm in 3-, 6-, 12- and
24-h periods over Alaska with more recent model data and
lightning observations. This updated guidance will take effect at
the beginning of the next warm season (May 1, 2016).
Communication identifiers for the products affected by this
update are listed in Tables 7 and 8 below.

Table 1: GRIB2 file names for the day 8-11 GFS-based Gridded MOS
elements (These files will reside in the VP.008-450 directory on
the ftp server.)

GRIB2 FILE NAME   ELEMENT
---------------   -----------------------------
ds.wdir.bin       Wind direction
ds.wspd.bin       Wind speed
ds.pop12.bin      12-h prob. of precipitation
ds.temp.bin       2-meter temperature
ds.td.bin         2-meter dew point temperature
ds.maxt.bin       Daytime maximum temperature
ds.mint.bin       Nighttime minimum temperature
ds.rhm.bin        Relative humidity

Table 2: WMO super headers for the day 8-11 Gridded MOS products
over the CONUS

WMO SUPERHEADER   ELEMENT
---------------   -----------------------------
YBUZ96 KWBQ       Wind direction
YCUZ96 KWBQ       Wind speed
YDUZ96 KWBQ       12-h prob. of precipitation
YEUZ96 KWBQ       2-meter temperature
YFUZ96 KWBQ       2-meter dew point temperature
YGUZ96 KWBQ       Daytime maximum temperature
YHUZ96 KWBQ       Nighttime minimum temperature
YRUZ96 KWBQ       Relative humidity

Table 3: WMO super headers for the day 8-11 Gridded MOS products
over Alaska

WMO SUPERHEADER   ELEMENT
---------------   -----------------------------
LBRZ96 KWBQ       Wind direction
LCRZ96 KWBQ       Wind speed
LDRZ96 KWBQ       12-h prob. of precipitation
LERZ96 KWBQ       2-meter temperature
LFRZ96 KWBQ       2-meter dew point temperature
LGRZ96 KWBQ       Daytime maximum temperature
LHRZ96 KWBQ       Nighttime minimum temperature
LRRZ96 KWBQ       Relative humidity

Table 4. WMO superheaders for each 2.5-km CONUS Gridded MOS
element affected by the grid expansion.  Listed below are
representations of the superheaders where ii=98 for short-range
guidance (days 1-3) and ii=97 for medium-range guidance (days 4-
7). Elements indicated by (**) will include ii=96 for extra
extended-range (days 8-11).

WMO SUPERHEADER   ELEMENT
---------------   -----------------------------
YAUZii KWBQ       Total sky cover
YBUZii KWBQ**     Wind direction
YCUZii KWBQ**     Wind speed
YDUZii KWBQ**     12-h prob. of precipitation
YEUZii KWBQ**     2-meter temperature
YFUZii KWBQ**     2-meter dew point temperature
YGUZii KWBQ**     Daytime maximum temperature
YHUZii KWBQ**     Nighttime minimum temperature
YIUZii KWBQ       6-h quant. precipitation amount
YRUZii KWBQ**     Relative humidity
YSUZii KWBQ       24-h snowfall amount
YUUZii KWBQ       6-h prob. of precipitation
YVUZii KWBQ       12-h quant. precipitation amount
YWUZii KWBQ       Wind Gusts

Table 5:  Communication identifiers for the GFS-based COOP
maximum and minimum temperature text products affected by the
changes

WMO HEADING       AWIPS ID
-----------       --------
FOUS10 KWNO       MCGUSA   (Short-range)
FEUS10 KWNO       MCXUSA   (Extended-range)

Table 6: Communication identifiers for the GFS-based River
Forecast Center SHEF products affected by the changes

   WMO HEADING      AWIPS ID
   -----------      --------
   FOUS12 KWNO      FTPCIN
   FOUS12 KWNO      FTPHFD
   FOUS12 KWNO      FTPKRF
   FOUS12 KWNO      FTPMSR
   FOUS12 KWNO      FTPPTR
   FOUS12 KWNO      FTPRHA
   FOUS12 KWNO      FTPRSA
   FOUS12 KWNO      FTPSLR
   FOUS12 KWNO      FTPTUR
   FOAK12 KWNO      FTPACR

Table 7: Communication identifiers for the GFS-based MOS text
products affected by the updated Alaska thunderstorm guidance

   WMO HEADING      AWIPS ID
   -----------      --------
   FOAK37 KWNO      MAVAJK
   FOAK38 KWNO      MAVAFC
   FOAK39 KWNO      MAVAFG
   FEAK37 KWNO      MEXAJK
   FEAK38 KWNO      MEXAFC
   FEAK39 KWNO      MEXAFG

Table 8: Representations of WMO headers for the Alaska Gridded
MOS products affected by the updated thunderstorm guidance, where
XXX represents the valid day and time

WMO SUPERHEADER   ELEMENT
---------------   -----------------------------
   LJRXXX KWBQ     3-h Prob. of a thunderstorm
   LYRXXX KWBQ     6-h Prob. of a thunderstorm
   LXRXXX KWBQ     12-h Prob. of a thunderstorm

For questions regarding the above changes to the GFS-based MOS
guidance, please contact:

  Phil Shafer
  MDL/Silver Spring, Maryland
  301-427-9488
  Phil.Shafer@noaa.gov
or
  Matthew Peroutka
  MDL/Silver Spring, Maryland
  301-427-9483
  Matthew.Peroutka@noaa.gov

Links to MOS products and descriptions are online at:

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

National Technical Implementation Notices are online at:

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

$$



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