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The Federal Aviation Administration (FAA) owns, operates and maintains Terminal Doppler Weather Radars (TDWRs) at 45 major airports around the nation to provide wind shear and other critical weather data to air traffic controllers supporting safe flight operations. The FAA also allows the National Weather Service (NWS) access to TDWR data for NWS forecast operations. NWS developed TDWR Supplemental Product Generators (SPGs) to bring TDWR data into selected NWS forecast offices. This data includes finished, NWS-oriented radar products to be used during forecast and emergency warning operations.

Each SPG hosts software for communication to the TDWR radar, NWS product generation, local storage and distribution control of the resultant NWS-oriented TDWR radar data. Each SPG monitors the operational status of the SPG system and provides a human-computer interface (HCI) to allow local forecasters and maintenance personnel control, monitoring, and troubleshooting capability.

The ROC is responsible for the life cycle management and support of TDWR SPG hardware and software. This includes:

  1. SPG operations and technical/maintenance manuals
  2. Engineering the replacement of obsolete hardware components
  3. Investigating and implementing SPG requests for change
  4. Software maintenance, change development, and security         

Local forecast offices are responsible for individual SPG equipment physical security, day to day SPG operation and maintenance and change request submission via an approved ROC change process.

Current Work

  1. Development of SPG Build 12.0, to be released in 2022, which will include:
    1. Security updates and bug fixes
    2. Porting of Graphical User Interfaces (GUIs) from X/Motif to the GTK+ language to increase supportability and maintainability
    3. Minor updates to the locations of the TDWRs in the ROC’s database and the published Level III data, based on a new list provided by the FAA
    4. An improved data handling routine for interprocess communication in the Tornadic Vortex Signature (TVS) product, as part of the broader process of migrating legacy algorithms from FORTRAN to C for maintainability.
  2. Analysis of how best to migrate and update TDWR SPG communications as part of the Government wide transition to the new Enterprise Infrastructure Solutions (EIS) communications contract.
  3. Planning for future modifications to fielded equipment, such as an upcoming refresh of the computers used to process TDWR SPG data.

TDWR SPG Project Overview

  1. High Level Overview from 2020 (PDF)
  2. Detailed Training Slides from 2020 (PPT)
  3. AMS IIPS 2009 Paper (PDF)
  4. AMS IIPS 2008 Paper (PDF) and Presentation (PPT)
  5. Radar Coverage Maps, Including TDWR (PDF)
  6. SPG Documentation on the ROC Website
  7. TDWR SPG Operational Radar Status
    1. Using Level II data via NL2
    2. Using Level III data via NCEP

Data Distribution

  1. Product Archives and System Information available via the National Center for Environmental Information (NCEI)
  2. Public Announcements affecting TDWR SPG data from 2018 to present are available via, including Service Change Notices and Public Information Statements. Older statements are available via an archive
  3. TDWR SPG Level II data
    1. Can be verified by filtering for the relevant ICAO on the Level II LDM page
    2. Archived and real time data available on Amazon Web Services and Google Cloud
  4. TDWR SPG Level III data via Radar Product Central Collection Dissemination Service (RPCCDS)
    1. RPCCDS Home Page
    2. January 2009 NWS Family of Services Meeting Briefing (TDWR SPG ONLY) (PDF)
    3. June 2008 NWS Family of Services Meeting Briefing (PDF)

TDWR Elevation Angles

  1. Build 1 vs Build 2
  2. Elevation Angles of Collected Products for Build 2