Three reasons. First, weather is the single largest variable in whether a VFR flight is safe, comfortable, or possible at all. The decisions you make at the planning table, go, no-go, divert, delay, are almost all driven by weather. Second, in flight, weather shapes what the aeroplane will do: turbulence, icing, performance loss in hot conditions, wind shear on approach. Third, weather is what kills general aviation pilots. The biggest single accident category is VFR flight into Instrument Meteorological Conditions (IMC); icing, thunderstorm penetration, and wind shear on approach round out the list. Met theory is the substrate for the airmanship that keeps you out of these traps.
There are two scales of weather worth distinguishing as you study:
Synoptic scale: the big patterns shown on charts: depressions, anticyclones, fronts, jet streams. Tens to thousands of kilometres. You plan around these.
Local scale: what's happening over your aerodrome and along your route in the next hour or so: gusts, visibility, isolated showers, sea breezes, hill fog. You fly around these.
Both matter, and they interact. A textbook frontal depression is a synoptic event; the cumulonimbus that drops a microburst on short final is a local event embedded within it.
Read the full section
Create a free account, just your email and a 6-digit code, to read the rest of Meteorology and save your progress across your devices.