6/17/21 AIM

Chapter 7. Safety of Flight Section 1.

7−1−1. Aviation gather weather information to support the needs of Weather Service Program the FAA and other users of the system. 5. a. Weather service to aviation is a joint effort of the Several NWS National Centers for Environ- National Oceanic and Atmospheric Administration mental Production (NCEP) provide aviation specific (NOAA), the National Weather Service (NWS), the weather forecasts, or select public forecasts which are Federal Aviation Administration (FAA), Department of interest to pilots and operators. of Defense, and various private sector aviation (a) The Aviation Weather Center (AWC) weather service providers. Requirements for all displays a variety of domestic and international aviation weather products originate from the FAA, aviation forecast products over the Internet at which is the Meteorological Authority for the U.S. aviationweather.gov. b. NWS meteorologists are assigned to all air (b) The NCEP Central Operations (NCO) is route traffic control centers (ARTCC) as part of the responsible for the operation of many numerical Center Weather Service Units (CWSU) as well as the weather prediction models, including those which Air Traffic Control System Command Center produce the many wind and temperature aloft (ATCSCC). These meteorologists provide special- forecasts. ized briefings as well as tailored forecasts to support (c) The (SPC) issues the needs of the FAA and other users of the NAS. tornado and severe weather watches along with other guidance forecasts. c. Aviation Products (d) The National Hurricane Center (NHC) 1. The NWS maintains an extensive surface, issues forecasts on tropical weather systems (for upper air, and radar weather observing program; and example, hurricanes). a nationwide aviation weather forecasting service. (e) The Space Weather Prediction Center 2. Airport observations (METAR and SPECI) (SWPC) provides alerts, watches, warnings and supported by the NWS are provided by automated forecasts for space weather events (for example, solar observing systems. storms) affecting or expected to affect Earth’s environment. 3. Terminal Aerodrome Forecasts (TAF) are (f) The Weather Prediction Center (WPC) prepared by 123 NWS Weather Forecast Offices provides analysis and forecast products on a national (WFOs) for over 700 airports. These forecasts are scale including surface pressure and frontal analyses. valid for 24 or 30 hours and amended as required. 6. NOAA operates two Volcanic Ash Advisory 4. Inflight aviation advisories (for example, Centers (VAAC) which issue forecasts of ash clouds Significant Meteorological Information (SIGMETs) following a volcanic eruption in their area of and Airmen’s Meteorological Information (AIR- responsibility. METs)) are issued by three NWS Meteorological 7. Watch Offices; the Aviation Weather Center (AWC) Details on the products provided by the above in Kansas City, MO, the Alaska Aviation Weather listed offices and centers is available in FAA eather Services. Unit (AAWU) in Anchorage, AK, and the WFO in Advisory Circular 00-45, Aviation W Honolulu, HI. Both the AWC and the AAWU issue d. Weather element values may be expressed by area forecasts (FA) for selected areas. In addition, using different measurement systems depending on NWS meteorologists assigned to most ARTCCs as several factors, such as whether the weather products part of the Center Weather Service Unit (CWSU) will be used by the general public, aviation interests, provide Center Weather Advisories (CWAs) and international services, or a combination of these

Meteorology 7−1−1