Of course, forecasters don’t just look out the window to prepare the weather report you see on TV. They use a sophisticated weather information network located all over—and above—the globe.
Satellites orbit the Earth constantly. Planes and balloons go up every day to gather data. Weather stations in almost every country on Earth send in data.
But forecasters still make mistakes. That’s because a forecast is only a prediction of what’s likely to happen, based on what’s going on now. But nature doesn’t always follow a predictable pattern. So a forecast is only a good guess, not a guarantee.