WEATHER By Jack Williams THE HOTTEST RECORDED temperature on Earth was 136 degrees Fahrenheit in El Azizia, Libya, in 1922. WHAT’S ABOVE AFFECTS YOU DOWN BELOW ven if you rarely expect to climb above 10,000 feet in an airplane you’re flying, understanding high-altitude weather will help you cope with weather closer to the ground. Weather is three-dimensional. What happened aloft a few hours ago can affect the weather you’ll face as you line up on the runway for takeoff. WEATHER IN DEPTH E KNOWING AT LEAST A LITTLE ABOUT HOW EVENTS HIGH ABOVE CAN AFFECT YOUR LOW-LEVEL FLIGHT WILL HELP YOU MAKE BETTER DECISIONS. Thunderstorms and their potential violence offer a good example. College or university programs for pilots normally require semesterlong meteorology courses that focus on the atmosphere. Most other student pilots learn mostly about surface and near-surface weather. For example, they learn that thunderstorms are most likely in warm air as an advancing cold front shoves the warm, humid air up to create thunderstorms. Pilots who have taken collegelevel meteorology know that what’s happening as high as 35,000 feet above the ground can make the difference between an afternoon with isolated “ordinary” thunderstorms that pilots can easily avoid and a tornado outbreak that can threaten airplanes parked in well-built hangars. Knowing at least a little about how events high above can affect your low-level flight will help you make better decisions about when to fly and when to wait and go another day. Such knowledge could tell you when you should be extra alert to potential weather dangers arriving sooner than forecast. EARLY IN THE TWENTIETH century, meteorologists who used telescopes to track balloons measured high-altitude winds as fast at 150 mph, but these seemed to be nothing but curi- 38 / FLIGHTTRAINING.AOPA.ORGhttp://FLIGHTTRAINING.AOPA.ORG