NOUS41 KWBC 131918



Technical Implementation Notice 16-19

National Weather Service Headquarters Washington DC

318 PM EDT Mon Jun 13 2016


To:         Subscribers

            -NOAA Weather Wire Service

            -Emergency Managers Weather Information Network


            Other NWS Partners and Employees


From:       Terrance J. Clark

            Director, Radar Operations Center


Subject:    Change in TDWR Elevation Angles Beginning

            July 18, 2016


The Federal Aviation Administration (FAA) will begin an upgrade

to Build 2.0 at all 45 Terminal Doppler Weather Radars (TDWRs)

starting about July 18, 2016. The FAA anticipates full

deployment will take approximately 2 years. TOKC (Oklahoma City,

OK) will be the first site to be upgraded.


Impacts to external users of NWS Supplemental Product Generator

(SPG) products are related to changes in elevation angles and

scanning strategies: 


1. The Long Range reflectivity angle will change and will be

different on a site-to-site basis. Previously, all sites used

0.6 degrees.


2. In Volume Coverage Pattern (VCP) 80, there will be an

additional 1.0 degree elevation angle each volume scan.


3. When a site is upgraded, the SPG General Status Message (GSM)

will report RDA build number 2.


More information on scanning changes related to TDWR Build 2.0

is available online:


For questions or comments, please contact:


      Jessica Schultz

      NWS Radar Focal Point

      Radar Operations Center


National Technical Implementation Notices are online at: