Aviation guide

Aviation weather explained

Pilots and controllers use a completely different weather vocabulary from the general public. Once you know the alphabet soup, aviation reports are the densest weather intel available anywhere.

METAR — the surface observation

A METAR is an hourly airport weather observation. It looks intimidating but has a rigid structure.

Example: KOKC 231553Z 18015G22KT 10SM FEW250 27/17 A2998 RMK AO2

KOKC — Oklahoma City airport identifier
231553Z — day 23, time 15:53 UTC (Zulu)
18015G22KT — wind from 180° at 15 knots, gusting 22
10SM — visibility 10 statute miles
FEW250 — few clouds at 25,000 ft
27/17 — temperature 27°C, dew point 17°C
A2998 — altimeter 29.98 inches Hg
RMK AO2 — remarks; AO2 means automated station with precipitation sensor

TAF — the terminal forecast

A TAF is a 24-30 hour forecast for an airport. Same format as METAR but with forecast segments.

Look for keywords: FM (from) starts a new segment, TEMPO means temporary conditions, PROB30 means 30% probability, BECMG means gradually becoming.

PIREP — pilot report

A PIREP is what a pilot reports back from the air. Turbulence, icing, mountain wave, cloud tops. PIREPs are what fill in the gaps between airport surface observations.

Prefix "UUA" = urgent (severe turbulence, severe icing). Prefix "UA" = routine.

SIGMET and AIRMET

SIGMET

Significant Meteorological Information. Warning of severe hazards — turbulence, icing, dust storms, volcanic ash. Issued when necessary.

AIRMET

Airmen's Meteorological Information. Advisories of moderate hazards — moderate turbulence, IFR conditions, mountain obscuration. Issued every 6 hours.

Convective SIGMET

Specific to thunderstorms. Issued for any storm cluster ≥40% coverage, embedded storms, or organized lines of storms.

The tools

aviationweather.gov — official NOAA/NWS aviation weather site
1800WXBRIEF.com — official flight briefing
ForeFlight ($99+/yr) — the standard pilot app
Windy Aviation layer — non-official but excellent visualization