Surface Observations
METAR (Meteorological Aerodrome Report)
The primary source for current airport weather conditions. METARs include wind, visibility, weather phenomena, cloud layers, temperature, dew point, and altimeter setting. Issued every 30-60 minutes. Read our full METAR decoder guide.
SPECI (Special Report)
An unscheduled METAR issued when significant weather changes occur between regular reporting times. Same format as METAR but triggered by sudden changes in conditions.
Forecasts
TAF (Terminal Aerodrome Forecast)
24-30 hour weather forecast for a specific airport. Uses change groups (FM, TEMPO, BECMG, PROB) to describe expected weather transitions. Essential for planning arrivals and considering alternate airports. Read our full TAF guide.
Area Forecasts
Broader weather forecasts covering large regions. Used for en-route weather assessment, especially for VFR flights. These complement TAFs by providing weather information between airports.
Warnings and Advisories
SIGMET (Significant Meteorological Information)
High-priority warnings for hazardous weather affecting all aircraft: severe turbulence, severe icing, volcanic ash, tropical cyclones, and embedded thunderstorms. Read our SIGMET/AIRMET guide.
AIRMET / GAMET
Advisories for weather hazardous primarily to light aircraft and VFR operations. Covers moderate turbulence and icing, IFR conditions, and mountain obscuration. GAMET is the ICAO equivalent used outside the US.
Pilot Reports
PIREP (Pilot Report)
Real-world weather observations reported by pilots in flight. These provide invaluable confirmation (or contradiction) of forecast conditions. PIREPs cover:
- Turbulence location, altitude, and intensity
- Icing type, intensity, and altitude
- Cloud tops and bases
- Visibility and weather phenomena
- Wind shear reports
The Complete Weather Briefing
A thorough pre-flight weather briefing should include:
| Product | Purpose | Check When |
|---|---|---|
| METAR | Current conditions | Before departure + before landing |
| TAF | Forecast conditions | Planning phase + alternate selection |
| SIGMET | Hazardous weather | Route analysis + go/no-go decision |
| AIRMET/GAMET | Advisory-level weather | Route analysis + altitude selection |
| NOTAMs | Operational hazards | All phases of flight planning |
| PIREPs | Real conditions aloft | Pre-departure + en-route updates |