NOUS41 KWBC 072100

PNSWSH

Technical Implementation Notice 11-04

National Weather Service Headquarters Washington DC

400 PM EST Mon Feb 7 2011

TO:        Subscribers:

           -Family of Services

           -NOAA Weather Wire Service

           -Emergency Managers Weather Information Network

           -NOAAPORT 

           Other NWS Partners and Employees

FROM:     Kevin Schrab       

          Chief, Observing Services Division 

          Office of Climate, Water, and Weather Services

SUBJECT:  Second Quarter 2011 Dates for Termination of 
 Automated Radiotheodolite Tracking (ART) and Radio 
 Direction Finding Radiosondes (RDF) with Installation
 of Radiosonde Replacement Systems (RRS)

Three Upper Air (UA) sites are scheduled to receive RRS 
Upgrades in the next 2 months in 2011:

STATION NAME   WMO #      STN ID    OUTAGE DATES

PAGO PAGO      91765      NSTU      08 Feb 2011

KOROR          91408      PTRO      09 Mar 2011

YAP            91413      PTYA      20 Mar 2011

These UA sites may be out of service for as long as 10 days.  
When the NWS UA observations resume, the RRS will be gathering
meteorological data from Global Positioning System (GPS) 
radiosondes. 

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:

  http://www.ua.nws.noaa.gov

Although the effective date for this notice is less than the 

30-days advised in 10-1805, this notice will be sufficient 
to inform users of the UA service outage at Pago Pago in 
American Samoa.  This site is managed by a Weather Service 
Office that is staffed 24-hours a day and the outage during 
typhoon season is considered low risk.

If you have questions or feedback, please contact:

  Ivan Navarro

  Engineering and Acquisition Branch (OPS11)

  National Weather Service

  1325 East West Highway

  Silver Spring, Maryland 20910

  301-713-1841 Ext. 123 

  Ivan.Navarro@noaa.gov

NWS National Technical Implementation notices are online:

  http://www.weather.gov/os/notif.htm

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