NOUS41 KWBC 211159 CCA



Technical Implementation Notice 13-14, Corrected

National Weather Service Headquarters Washington DC

758 AM EDT Jun 21 2013


TO:        Subscribers:

           -Family of Services

           -NOAA Weather Wire Service

           -Emergency Managers Weather Information Network


           Other NWS Partners and Employees


FROM:      Kevin Schrab      

           Chief, Observing Services Division

           Office of Climate, Water, and Weather Services


SUBJECT:   Corrected:  August 20, 2013, the first of three Alaska

           Upper Air Sites will Terminate its Automated

           Radiotheodolite Tracking (ART) and Radio Direction

           Finding Radiosondes (RDF) upon Installation of the

           Radiosonde Replacement System (RRS)


Corrected for proper WMO Numbers for McGrath and Cold Bay and to

increment TIN to 13-14.


Three Upper Air (UA) sites in Alaska are scheduled to begin RRS

service on or after August 20, 2013.




KOTZEBUE       70133      PAOT      20 Aug 2013

MCGRATH        70231      PAMC      30 Aug 2013

COLD BAY       70316      PACD      24 Sep 2013


These UA sites may be out of service for as long as 10 days. 

The NWS UA observations will gather meteorological data from

Global Positioning System (GPS) radiosondes of a new type, the

LMS-6.  The assigned equipment code is 48208. The leading 4

indicates a correction is applied for solar and infrared

exposure.  The 08 suffix indicates automatic satellite

navigation.  This code appears immediately after the heading,

31313 in the TTAA, TTBB, TTCC, and TTDD messages.


The NWS describes the RRS release point location with the

National Geodetic Survey (NGS) OPUS solution. This is a datum

combination that relies on North American Datum of 1983 (NAD83)

for latitude and longitude whereas the release point elevation

is based on North American Vertical Datum 1988 (NAVD88) with the

GEOID03 model.  By contrast the GPS radiosonde flight

information of latitude and longitude and altitude will rely on

the world geodetic system of 1984 (WGS84) standard.


Parts of the UA coded messages will be significantly longer with

RRS conversion.  NWS has coordinated with its partners on the

longer length of these messages.


The format of the messages will be the same WMO format for coded

UA messages used with the MicroArt legacy system. The number of

levels in the coded messages will be two to three times greater

for the TTBB and TTDD.  As a result two categories of AWIPS text

products will increase in size:  SGL and ABV. The number of

levels in the TTAA, TTCC, PPBB and PPDD parts will be relatively

unchanged. These changes reflect updated coding practices and

higher resolution level selection criteria. The maximum size

limits of the parts of the coded messages are as follows:


     TTAA:   15 Levels 

     TTCC:   10 Levels 

     TTBB:  135 Levels

     TTDD:   40 Levels

     PPBB:   40 Levels 

     PPDD:   40 Levels


In addition the 31313 message indicator associated with various

parts of the message will be included with each part of the

thermodynamic message parts.


For additional information on the message requirements please

see the WMO 306 Manual on Codes (International Codes):  Volume

I.1 Part A, Alphanumeric Codes and Volume II Regional Codes and

National Coding Practices. Users can find information on the

levels selection criteria used in NWS coding software online at:



If you have questions or feedback, please contact:


  Neal Dipasquale

  Acting Director, Field Systems Operations Center (OPS21)

  National Weather Service

  Silver Spring, Maryland 20910

  301-713-0039 Ext. 155



NWS National Technical Implementation notices are online at: