What is a METAR?

A METAR is an observation of current surface weather reported in a standard format.

METARs are issued on a regularly scheduled basis unless significant weather changes have occurred.  A special METAR (SPECI) can be issued at any time between routine METAR reports.  A typical METAR report contains the following information in sequential order: type of report, station identifier, date and time of report, modifier, wind, visibility, weather, sky condition, temperature and dew point, altimeter setting, Zulu time, remarks.

Example: METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB 18/17 A2970 RMK PRESFR

Explanation: Routine METAR for Gregg County Airport for the 16th day of the month at 1753Z automated source.  Winds are 140 at 21 knots gusting to 26. Visibility is 3⁄4 statute mile.  Thunderstorms with heavy rain and mist.  Ceiling is broken at 800 feet, overcast at 1,200 feet with cumulonimbus clouds.  Temperature 18 °C and dew point 17 °C.  Barometric pressure is 29.70Hg and the pressure is falling rapidly.


FAA AC 00-45H Aviation Weather Services pg. 3-1
FAA-H-8083-25B Pilot’s Handbook of Aeronautical Knowledge pg. 13-7

Other Aviation Weather Services

What is an Aviation Forecast Discussion?

The Aviation Forecast Discussion is a text interruption from a meteorologist of the local weather conditions.

Aviation Forecast Discussions (AFD) are issued by each weather service forecast office (WFO) to describe the weather conditions within their region as it relates to the creation of the TAF.  These are useful for additional aviation related issues that cannot be encoded into the TAF.  The discussion also gives some reasoning behind the forecast.  These are generated roughly every 6 hours and corresponds to the release of the latest TAFs for that office.  The aviation forecast discussion explains the aviation forecast in greater detail than a traditional TAF.  It highlights possible hazards in the forecast that may not be specifically mentioned in the TAF, possibly due to a low level of confidence that the event will occur.  The frequency of aviation discussion issuances varies between WFOs.



Other Aviation Weather Services

What is a PIREP?

Pilot weather reports (PIREPS) are weather observations provided by pilots.

PIREPs provide valuable information regarding the conditions as they actually exist in the air, which cannot be gathered from any other source.  Pilots can confirm the height of bases and tops of clouds, locations of wind shear and turbulence, and the location of inflight icing.  PIREPs are filed in a stand format: station identifier, type of report (routine or urgent), time, altitude/flight level, aircraft type, sky cover/cloud layers, weather, air temperature, wind, turbulence, icing and remarks. Below is an example.

KCMH UA /OV APE 230010/TM 1516/FL085/TP BE20/SK BKN065/WX FV03SM HZ FU/TA 20/TB LGT

Explanation:  This a routine PIREP. The pilot is reporting from one zero miles southwest of Appleton VOR;  the time of the report is 1516 UTC;  the altitude is eight thousand five hundred;  the aircraft type is a King Aire 200;  the bases of a broken cloud layer is at six thousand five hundred;  flight visibility 3 miles with haze and smoke;  the air temperature is 20 degrees Celsius and there is light turbulence.


AIM 2018 7−1−20. Pilot Weather Reports (PIREPs)
FAA AC 00-45H Aviation Weather Services pg. 3-6
FAA-H-8083-25B Pilot’s Handbook of Aeronautical Knowledge pg. 13-8

Other Aviation Weather Services