NOUS41 KWBC 071232



Technical Implementation Notice 16-15

National Weather Service Headquarters Washington DC

832 AM EDT Tue Jun 7 2016


To:       Subscribers:

          -NOAA Weather Wire Service

          -Emergency Managers Weather Information Network


          Other NWS Partners, Users and Employees


From:     Tim McClung

          Chief Operating Officer

          NWS Office of Science and Technology Integration


Subject:  Changes to North American Mesoscale Model

          (NAM)-based Model Output Statistics (MOS) Guidance

          Effective July 26, 2016


On or about Tuesday, July 26, 2016, beginning with the 1200

Coordinated Universal Time (UTC) model run, the NWS

Meteorological Development Laboratory (MDL) will implement

updates to the NAM-based MOS temperature and wind guidance. 

These updates will include new forecast equations for daytime

maximum and nighttime minimum temperature, 2-m temperature and

dewpoint, and 10-m wind speed and direction. MDL is updating

equations for both the warm and cool seasons. The new equations

are based on dependent data samples that include a significant

amount of operational and reforecast data from the latest

version of the model (NAM v3.1.0) implemented August 2014. These

equations should be better tuned to the NAM bias



Due to changes in reporting frequencies, sufficient data were

not available for development of new temperature and/or wind

guidance at a number of sites currently included in the NAM MOS

system. Conversely, it was possible to develop guidance at a

number of sites not currently having forecasts for these

elements. A complete listing of these changes for both the warm

and cool seasons may be found on the MDL website at:


The upcoming changes will slightly alter the format of the NAM

MOS alphanumeric (MET/MME) and BUFR messages because lines will

be added or removed in response to the changes in availability

of forecast guidance listed in the tables below. No other

changes to the format of the NAM MOS messages are expected with

this update.


Beginning approximately 1 month prior to the implementation

date, 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 nam_mos.YYYYMMDD):


The following public weather alphanumeric messages and BUFR

products are affected by the above changes:


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

weather text products


     WMO HEADING    AWIPS ID      


     FOAK47 KWNO    METAJK        


     FOAK49 KWNO    METAFG        

     FOPA40 KWNO    METPA0        

     FOUS44 KWNO    METNE1        

     FOUS45 KWNO    METSE1        

     FOUS46 KWNO    METNC1        

     FOUS47 KWNO    METSC1        

     FOUS48 KWNO    METRM1        

     FOUS49 KWNO    METWC1        


Table 2: Communication identifiers for the NAM-based MOS marine

text products.




     FQAK47 KWNO    MMEAK1

     FQPA40 KWNO     MMEHI1   

     FQUS41 KWNO    MMENE1

     FQUS42 KWNO    MMESE1

     FQUS43 KWNO    MMEGL1

     FQUS44 KWNO    MMEGF1

     FQUS45 KWNO    MMENW1

     FQUS46 KWNO    MMESW1


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





     JSML10 KWNO

     JSML11 KWNO

     JSML12 KWNO

     JSML13 KWNO

     JSML14 KWNO

     JSML15 KWNO

     JSML16 KWNO

     JSML17 KWNO


For questions regarding the updates to the NAM MOS guidance and

associated message changes please contact:


  Mark Antolik

  MDL/Silver Spring, Maryland



  Matthew Peroutka

  MDL/Silver Spring, Maryland



Links to the MOS products and descriptions are online at:


NWS National Technical Implementation Notices are online at: