Of course, forecasters don’t just look out the window to prepare the weather report you see on TV. They use a fancy information network that’s all over—and above—the globe.
Satellites are always orbiting the Earth. Planes and balloons go up every day to get information. Weather stations in almost every country send in data.
Even so, forecasters still make mistakes. That’s because a forecast is only a guess of what is likely to happen. But it’s based on what is already happening, and nature doesn’t always follow a pattern we can see. So a forecast is only a good guess. It’s not a guarantee.