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Federal Aviation Administration Weather Services

Introduction:

  • 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

Observations:

  • 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

Sources:

  • The FAA provides the Flight Service program, which serves the weather needs of pilots through its flight service stations (FSS) (both government and contract via 1-800-WX-BRIEF) and via the Internet, through CSC Direct User Access Terminal System (DUATS) and Lockheed Martin Flight Services (DUATS II)
  • The FAA maintains an extensive surface weather observing program. Airport observations (METAR and SPECI) in the U.S. are provided by automated observing systems. Various levels of human oversight of the METAR and SPECI reports and augmentation may be provided at select larger airports by either government or contract personnel qualified to report specified weather elements that cannot be detected by the automated observing system
  • Other sources
    • 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
  • Pilots with a current medical certificate can access the Direct User Access Terminal System (DUATS) and Lockheed Martin Flight Services via the Internet. Pilots can receive preflight weather data and file domestic VFR and IFR flight plans. The following are the FAA contract vendors:
    • Computer Sciences Corporation (CSC)
    • Internet Access: http://www.duats.com
    • For customer service: (800) 345−3828
    • Lockheed Martin Flight Services
    • Internet Access: http://www.1800wxbrief.com
    • For customer service: (866) 936−6826
  • FAA and NWS Telephone Numbers (Chart Supplement U.S.)
    Figure 1: FAA and NWS Telephone Numbers (Chart Supplement U.S.)
  • Discrete frequencies for individual stations are listed in the Chart Supplement U.S.

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

Hazardous In-Flight Weather Advisory Service (HIWAS):

  • Broadcasted on selected VORs, recognized by a black circle with a white H

References: