NOUS41 KWBC 141135 AAA



Technical Implementation Notice 16-15

National Weather Service Headquarters Washington DC

735 AM EDT Thu Jul 14 2016


To:       Subscribers:

          -NOAA Weather Wire Service

          -Emergency Managers Weather Information Network


          Other NWS Partners, Users and Employees


From:     Tim McClung

          Portfolio Manager,

          NWS Office of Science and Technology Integration


Subject:  Amended: Changes to North American Mesoscale Model

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

          Effective August 16, 2016


Amended to change the implementation date from Tuesday, July 26,

2016, to Tuesday, August 16, 2015, and to change the locations

from which NAM MOS forecasts will be available for public



On or about Tuesday, August 16, 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. Equations are being

updated 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 in August 2014. 

Therefore, these equations should be better tuned to current

operational NAM bias characteristics. 


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 above tables. No other

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

this update.


Before the implementation date, users may download parallel NAM

MOS data from NOAA's Operational Model Archive and Distribution

System (NOMADS) at the following link:


Parallel BUFR products will reside in: metbufr.xtrn.nam_mos_XX,

NAM CONUS/OCONUS text products (MET) in: nammet.tran.nam_mos_XX,

and NAM marine products (MME) in: nammme.tran.nam_mos_XX, where

XX denotes the particular forecast cycle (00 for 0000 UTC, and

12 for 1200 UTC).


With this implementation, NCEP Central Operations (NCO) also

will be changing the address of servers from which the

operational NAM MOS forecasts will be available for public

download. Specifically, for the NAM MOS CONUS/OCONUS products

(MET), the current location:



will change to:

MDD/mdl_nammet.tXXz ,


and for the NAM MOS Marine products (MME), the current server




will change to:



where XX represents the particular forecast cycle (either 00 or

12 UTC), and YYYYMMDD the 8-digit year, month and date of the

NAM MOS forecasts requested. Users who rely upon these servers

for dissemination of these data should make preparations to

ingest data from the new locations.


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: