Federal Aviation Administration Weather Services


  • The National Weather Service maintains a network of radar sites for detecting coverage, intensity, and movement of precipitation, as well as Flight Service Stations (FSSs) to serve the weather needs of pilots
    • Local warning radar sites augment the network by operating on an as needed basis to support warning and forecast programs
  • NWS meteorologists are assigned to most Air Route Traffic Control Centers (ARTCCs) as part of the Center Weather Service Unit (CWSU)
    • They provide Center Weather Advisories (CWAs) and gather weather information to support the needs of the Federal Aviation Administration (FAA) and other users to the system



  • Scheduled radar observations are taken hourly and transmitted in alpha-numeric format on weather telecommunications circuits for flight planning purposes
  • Under certain conditions, special radar reports are issued in addition to the hourly transmittals
  • Data contained in the reports are also collected by the National Center for Environmental Prediction and used to prepare national radar summary charts for dissemination on facsimile circuits
  • A clear radar display (no echoes) does not mean that there is no significant weather within the coverage of the radar site
  • Clouds and fog are not detected by the radar
  • However, when echoes are present, turbulence can be implied by the intensity of the precipitation, and icing is implied by the presence of the precipitation at temperatures at or below zero degrees Celsius
  • Used in conjunction with other weather products, radar provides invaluable information for weather avoidance and flight planning
  • All En Route Flight Advisory Service facilities and FSSs have equipment to directly access the radar displays from the individual weather radar sites
  • Specialists at these locations are trained to interpret the display for pilot briefing and inflight advisory services
  • The Center Weather Service Units located in ARTCCs also have access to weather radar displays and provide support to all air traffic facilities within their center’s area



    • The primary source of preflight weather briefings is an individual briefing obtained from a briefer at the FSS
    • These briefings, which are tailored to your specific flight, are available 24 hours a day through the use of the toll free number (1-800-WX-BRIEF)
    • Numbers for these services can be found in the Airport Facility Directory (A/FD) under “FAA and NWS Telephone Numbers” section
      • They may also be listed in the U.S. Government section of your local telephone directory under Department of Transportation, Federal Aviation Administration
      • Our preflight briefing section explains the types of preflight briefings available and the information contained in each
    • Telephone Information Briefing Service (TIBS) (FSS); and in Alaska, Transcribed Weather Broadcast (TWEB) locations, and telephone access to the TWEB (TEL-TWEB) provide continuously updated recorded weather information for short or local flights
    • Weather and aeronautical information are also available from numerous private industry sources on an individual or contract pay basis
    • Information on how to obtain this service should be available from local pilot organizations
  • DUATS:

    • The Direct User Access Terminal System (DUATS) and Lockheed Martin Flight Services with a current medical certificate via the internet
    • Pilots can receive preflight weather data and file domestic VFR and IFR flight plans
    • The following are the contract DUATS vendors:
      • Computer Sciences Corporation (CSC)
      • Internet Access: http://www.duats.com
      • For customer service: (800) 345−3828
      • Data Transformation Corporation (DTC)
      • Internet Access: http://www.duat.com
      • For customer service: (800) 243−3828
      • Lockheed Martin Flight Services
      • Internet Access: http://www.1800wxbrief.com
      • For customer service: (866) 936−6826
  • FAA and NWS Telephone Numbers (A/FD)
    Figure 1: FAA and NWS Telephone Numbers (A/FD)


  • In-flight weather information is available from any FSS within radio range
  • The common frequency for all AFSSs is 122.2
  • Discrete frequencies for individual stations are listed in the A/FD
  • Next Generation Radar (NEXRAD) (CONUS and Regional):

    • Derived from Next Generation Weather Radar (WSR-88D). Radar mosaic consists of multiple single site radar images combined to produce a graphical image on a regional or national scale. Regional and national radar mosaics can be found at the National Weather Service (NWS) Doppler Radar Images web site: http://radar.weather.gov/ridge/
    NEXRAD Coverage
    Figure 2: NEXRAD Coverage
    NEXRAD Coverage
    Figure 4: NEXRAD Coverage
    NEXRAD Coverage
    Figure 3: NEXRAD Coverage