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WeatherWeather
Weather is where most flights begin and end. These guides decode the reports and forecasts pilots read every day, from METARs and TAFs to winds aloft, icing and convective hazards, and explain what each field is actually telling you.
15 guides
- Weather
How to read a surface analysis chart
Decode a surface analysis chart: isobars and the pressure gradient, highs and lows, warm, cold and occluded fronts, and what the big picture tells you before you read the METAR.
3 min read Read - Weather
The International Standard Atmosphere (ISA)
What the ICAO International Standard Atmosphere is, its sea-level values and lapse rate, and how ISA deviation underpins altimetry, performance and density altitude.
3 min read Read - Weather
How to read a SIGMET and an AIRMET
What SIGMETs and AIRMETs warn of, the phenomena codes, how long each stays valid, and a worked SIGMET decoded field by field, with the ICAO baseline and the US differences.
5 min read Read - Weather
How to read a METAR
A plain-language guide to decoding a METAR field by field, with a worked example and the EASA/UK and FAA differences that trip pilots up.
5 min read Read - Weather
How to read a TAF
Decode a Terminal Aerodrome Forecast, including the FM, BECMG, TEMPO and PROB change groups, the validity period, and how a forecast differs from a METAR observation.
4 min read Read - Weather
Density altitude and aircraft performance
What density altitude is, how to estimate it from pressure altitude and temperature, and why high, hot and humid conditions quietly rob an aircraft of performance.
4 min read Read - Weather
Aircraft icing explained
How airframe ice forms, the difference between rime, clear and mixed ice, what makes supercooled large droplets so dangerous, and where to find the icing forecast.
5 min read Read - Weather
Altimetry: QNH, QFE and the standard setting
What QNH, QFE and the standard pressure setting actually do to your altimeter, the difference between transition altitude and transition level, and the EASA and FAA conventions that differ.
5 min read Read - Weather
Fog, mist and the dewpoint spread
Why the gap between temperature and dewpoint predicts fog, the difference between mist and fog in a METAR, and the main fog types from radiation to advection.
8 min read Read - Weather
Wind shear and low-level wind shear
What wind shear is, why microbursts and gust fronts are so dangerous near the ground, how it changes an aircraft's performance, and the warnings and forecasts that flag it.
8 min read Read - Weather
Thunderstorms and convective weather
What makes a thunderstorm, the three stages of its life, the hazards from turbulence to hail and microbursts, and how the convective SIGMET warns you, with avoidance distances from the FAA.
8 min read Read - Weather
Setting personal weather minimums
What personal minimums are, how to build a set from ceiling, visibility and wind, and how to use the PAVE and IMSAFE checklists to keep your own limits honest.
7 min read Read - Weather
Flight rules: VFR, MVFR, IFR and LIFR
What the colour-coded flight categories mean, the exact ceiling and visibility boundaries set by the NWS and FAA, and why a flight category is not the same as the legal VFR minima.
7 min read Read - Weather
Reading winds and temperatures aloft
How to decode a winds and temperatures aloft forecast field by field, including the coding trick for strong winds, with a worked example and how to use it for cruise planning.
8 min read Read - Weather
How to read an ATIS
What the ATIS broadcast contains, how the information letter and runway-in-use work, how it differs from a METAR, and the EASA/UK and FAA conventions that trip pilots up.
7 min read Read