NOUS41 KWBC 041102 AAA

PNSWSH

 

Technical Implementation Notice 12-25 Amended

National Weather Service Headquarters Washington DC

702 AM EDT Mon Jun 4 2012

 

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:  Amended: Update to GFS-based Model Output Statistics

          (MOS) Wind Guidance and resulting changes to LAMP wind

          guidance: Implementation postponed to June 12, 2012.

 

Amended to postpone implementation to June 12, 2012

 

On Tuesday, June 12, 2012, beginning with the 1200 Coordinated

Universal Time (UTC) model cycle, the NWS Meteorological

Development Laboratory will implement new Global Forecast System

(GFS)-based Model Output Statistics (MOS) wind speed and

direction guidance for sites available in the short-range (MAV)

and extended-range (MEX) text bulletins. These new equations

correct bias changes in the GFS model upgrade implemented May

10, 2011:

 

www.nws.noaa.gov/os/notification/tin11-07gfs_update_aaa.htm

 

 

These changes also will impact the GFS-based Localized Aviation

MOS Program (LAMP) beginning with the 1600 UTC Run.  

 

Geographic expanses of certain vegetation types in the southern

and western United States correspond to areas where degradation

in the MOS wind guidance was most evident, particularly in the

warm season. Wind equations are being replaced for most stations

over the CONUS. The GFS model upgrade has shown little impact on

MOS guidance over ocean water so the current set of equations

for all marine stations will remain in place. Guidance for

stations in Alaska and neighboring Canadian sites also are not

being replaced at this time because verification of the new

equations shows a slight degradation in skill.

 

Three METAR sites in the West no longer report or do not contain

a sufficient number of wind observations from which to develop

new equations. Forecasts produced from the old equations are

significantly degraded. Guidance for wind direction and speed

will be missing for the following three sites for all cycles and

projections in the MAV and MEX bulletins:

 

     K4BM      Wilkerson Pass, CO

     KBJN      Tonopah Range 74 Nellis AFB, NV

     KTDO      Toledo-Winlock Memorial, WA

 

As a result of the GFS MOS change above, LAMP guidance for wind

direction, speed, and gusts will now be missing for the

following site for all cycles and projections in the LAMP LAV

bulletins and BUFR messages:

 

     KTDO      Toledo-Winlock Memorial, WA

 

In addition, guidance for wind direction and speed has been

added for the following two Air Force sites for all cycles and

projections in the Air Force MAV and MEX bulletins:

 

     KBYS      Bicycle Lake Army Airfield, CA

     KL35      Big Bear City Airport, CA

 

These changes will slightly alter the format of the MAV and MEX

text products because lines for wind direction and speed will be

added or removed for the 5 sites listed above.  These changes

will slightly alter the format of the LAV text products because

lines for wind direction, speed, and gusts will be removed for

the 1 site listed above.  The tables below list the

communication identifiers for all products affected by these

changes.

 

A temporary Website has been made available until the new

equations are implemented so users may compare the current

operational GFS MOS wind speed with the improved GFS MOS wind

speed guidance.  The comparison page can be found at:

 

  http://www.mdl.nws.noaa.gov/~mos/mos/gfsmos_wind/

 

Table 1: Communication identifiers for the GFS-based MOS public

text products affected by the changes.

 

     WMO HEADING   AWIPS ID   WMO HEADING   AWIPS ID

         (SHORT RANGE)           (EXTENDED RANGE)

     --------------------     ----------------------

     FOPA20 KWNO   MAVPA0     FEPA20 KWNO   MEXPA0

     FOUS21 KWNO   MAVNE1     FEUS21 KWNO   MEXNE1

     FOUS22 KWNO   MAVSE1     FEUS22 KWNO   MEXSE1

     FOUS23 KWNO   MAVNC1     FEUS23 KWNO   MEXNC1

     FOUS24 KWNO   MAVSC1     FEUS24 KWNO   MEXSC1

     FOUS25 KWNO   MAVRM1     FEUS25 KWNO   MEXRM1

     FOUS26 KWNO   MAVWC0     FEUS26 KWNO   MEXWC0

 

Table 2: Communication identifiers for the affected Air Force

MOS text products.

   

     WMO HEADING   AWIPS ID   WMO HEADING   AWIPS ID

         (SHORT RANGE)           (EXTENDED RANGE)

     ---------------------    ----------------------

     FOUS30 KWNO   MAVF26     FEUS30 KWNO   MEXF26

 

Table 3. Communication identifiers for the GFS-based MOS BUFR

products affected by the changes.

 

     WMO HEADING    WMO HEADING   REGION

    (SHORT RANGE)  (EXTENDED RANGE)

     ------------   -----------   ------------------   

     JSML30 KWNO    JSMT30 KWNO   PACIFIC REGION

     JSML31 KWNO    JSMT31 KWNO   NORTHEAST CONUS

     JSML32 KWNO    JSMT32 KWNO   SOUTHEAST CONUS

     JSML33 KWNO    JSMT33 KWNO   NORTH CENTRAL CONUS

     JSML34 KWNO    JSMT34 KWNO   SOUTH CENTRAL CONUS

     JSML35 KWNO    JSMT35 KWNO   ROCKY MOUNTAIN CONUS

     JSML36 KWNO    JSMT36 KWNO   WEST COAST CONUS

    

Table 4: Communication identifiers for the GFS-based LAMP public

text product affected by the changes.

 

     WMO HEADING   AWIPS ID

     -----------   --------  

     FOUS11 KWNO   LAVUSA

 

Table 5: Communication identifiers for the GFS-based LAMP BUFR

products affected by the changes.

 

     WMO HEADING   REGION

     ------------  ---------------

     JSMF10 KWNO   PACIFIC REGION

     JSMF11 KWNO   NORTHEAST CONUS

     JSMF12 KWNO   SOUTHEAST CONUS

     JSMF13 KWNO   NORTH CENTRAL CONUS

     JSMF14 KWNO   SOUTH CENTRAL CONUS

     JSMF15 KWNO   ROCKY MOUNTAIN CONUS

     JSMF16 KWNO   WEST COAST CONUS

   

For questions regarding the update to the GFS MOS wind guidance

and resulting changes to the MAV and MEX bulletins contact:

 

  Kathryn Gilbert

  MDL/Silver Spring, Maryland

  301-713-0023, Ext. 130

  Kathryn.Gilbert@noaa.gov

 

For questions regarding the changes to LAMP guidance contact:

 

  Judy Ghirardelli

  MDL/Silver Spring, Maryland

  301-713-0056, Ext. 194

  Judy.Ghirardelli@noaa.gov

 

Links to the MOS products and descriptions are online at:

 

  http://www.nws.noaa.gov/mdl/synop

 

NWS national Technical Implementation Notices are online at:

 

  http://www.weather.gov/os/notif.htm

 

$$