12.aviation-weather-center-resources. Aviation Weather Center (AWC) Resources
The Aviation Weather Center (AWC), operated by the National Weather Service (NWS) in Kansas City, Missouri, is the FAA-designated source of aviation weather forecasts, advisories, and analyses for the contiguous United States. Its public-facing website, aviationweather.gov, consolidates products that pilots are expected to consult during preflight planning under 14 CFR §91.103, and it is one of the primary tools recognized for satisfying the requirement to obtain "all available information concerning the flight."
AWC products are organized around three mission areas: observations, forecasts, and advisories. Pilots should be familiar with the principal products in each category and how to interpret them.
Observation products:
- METAR — Routine surface observation issued hourly, with SPECI reports for significant changes. Reports wind, visibility, weather, sky condition, temperature/dew point, altimeter, and remarks.
- PIREP/AIREP — Pilot-submitted reports of actual conditions aloft (turbulence, icing, cloud tops, ride quality). AWC plots these on the Java/HTML PIREP map.
- Radar Mosaic — Composite of NEXRAD WSR-88D returns showing precipitation intensity. Useful but lags real time by several minutes; not for tactical thunderstorm avoidance.
- Satellite imagery — Visible, infrared, and water-vapor channels from GOES.
- Ceiling & Visibility Analysis (CVA) — A gridded product depicting current flight category (VFR, MVFR, IFR, LIFR) interpolated from METAR sites.
Forecast products:
- TAF — Terminal Aerodrome Forecast, valid 24 or 30 hours, issued four times daily, covering a 5 SM radius around the airport.
- Area Forecast Discussion (AFD) and Graphical Forecasts for Aviation (GFA) — The GFA tool replaced the textual Area Forecast (FA) for the CONUS in 2017. It presents observations, warnings, and forecasts of clouds, visibility, winds, icing, turbulence, and precipitation in 3-hour increments out to 15 hours, plus a 14-hour outlook.
- Winds and Temperatures Aloft (FB) — Forecasts at standard levels (3,000; 6,000; 9,000; 12,000; 18,000; 24,000; 30,000; 34,000; 39,000 ft). Direction is true, speed in knots; temperature in °C is assumed negative above 24,000 ft.
- Prog Charts — Surface and low-/mid-/high-level significant weather charts depicting fronts, pressure systems, and forecast hazards.
Advisory products (in-flight hazards):
- AIRMET (WA) — Issued every 6 hours, amended as needed, for hazards of lesser intensity than SIGMETs:
- AIRMET Sierra — IFR ceilings/visibility and mountain obscuration
- AIRMET Tango — Moderate turbulence and surface winds ≥30 kt
- AIRMET Zulu — Moderate icing and freezing levels
- SIGMET (WS) — Severe icing not associated with thunderstorms, severe or extreme turbulence, widespread duststorms or sandstorms reducing visibility below 3 SM, and volcanic ash. Valid up to 4 hours (6 hours for volcanic ash and hurricanes).
- Convective SIGMET (WST) — Severe thunderstorms, embedded thunderstorms, lines of thunderstorms, or areas with thunderstorm coverage ≥40% over 3,000 sq mi. Issued hourly at H+55, valid 2 hours.
- Center Weather Advisory (CWA) — Unscheduled, short-fuse advisory issued by the Center Weather Service Unit (CWSU) for conditions meeting or approaching SIGMET/AIRMET criteria, valid up to 2 hours.
Specialized tools on aviationweather.gov:
- G-AIRMET — Graphical AIRMET in 3-hour snapshots out to 12 hours.
- Icing (CIP/FIP) — Current and Forecast Icing Products show probability, severity, and supercooled large droplet (SLD) potential at altitude slices.
- Turbulence (GTG) — Graphical Turbulence Guidance forecasts CAT and mountain-wave turbulence by altitude.
- Ceiling/Visibility, Flight Path Tool, and Helicopter Emergency Medical Services (HEMS) Tool — Cross-section and route-based depictions for tailored planning.
- Volcanic Ash Advisories (VAA) and Tropical products — Issued in coordination with VAACs and the National Hurricane Center.
Using AWC for preflight planning. A practical workflow is to start with the GFA for a regional picture, drill down to METARs and TAFs along the route and at alternates, review PIREPs and radar/satellite for current conditions, and finish with the AIRMET/SIGMET/CWA layer plus winds aloft for fuel and altitude selection. AWC products complement, but do not replace, a standard briefing from Flight Service (1-800-WX-BRIEF or 1800wxbrief.com), which logs the briefing for legal purposes. Pilots should also note that aviationweather.gov is informational; in flight, HIWAS legacy broadcasts have been discontinued, and hazardous weather is now disseminated through Flight Watch/Flight Service frequencies and via FIS-B on ADS-B In equipment.