Weather forecasts—particularly any forecasts related to aviation—adhere to it; upper air analyses and prognoses have it appended to them; hourly weather observations around the world abide by it; and weather balloons launched worldwide cater to it. Nationally and globally, the weather forecasting network runs on international time denoted by the sometimes puzzling “Z,” known phonetically as “Zulu.” Although the average regional weather forecast probably references local time, wherever that might be, on a grander scale “Zulu” rules.
Logistically, anything transiting the Earth must reference international time. Aviation, shipping, air traffic control, global communications, the orbiting space shuttle, and military operations top the list. Weather forecasts and observations are
another area.
—DOUG MORRIS is a certified meteorologist and a pilot for Air Canada. He is the author of From the Flight Deck: Plane Talk and Sky Science.
