☁️ Clouds and atmosphere

Clouds come in a few main families based on their shape and how high they float, wispy, thin clouds high in the sky, puffy, cotton-like clouds in the middle, and flat, layered clouds that often blanket the whole sky. Each type tends to mean something different about the weather coming, tall, towering clouds often mean a storm is building, while thin, high clouds usually mean calm weather is still a day or two away. Meteorologists study cloud shapes closely because they are one of the best free clues about what the sky is about to do.

The atmosphere is the layer of gases wrapped around Earth, mostly nitrogen and oxygen, with tiny amounts of other gases mixed in, and it is what you breathe and what all weather happens inside of. It gets thinner the higher up you go, which is why mountain climbers on the tallest peaks sometimes need extra oxygen to breathe. Without the atmosphere trapping some of the sun's heat, Earth would be far too cold for anything to survive.

Air pressure is how hard the air above you is pressing down, and it changes as air warms, cools, rises or sinks in different places, creating areas of higher and lower pressure across the sky. Warm air rises and spreads out, which lowers pressure underneath it, while cool air sinks and piles up, which raises pressure. Meteorologists track these shifting pressure areas closely, since air always flows from high pressure toward low pressure, and that flow is exactly what creates wind and storms.

Meteorologists gather huge amounts of information, temperature, humidity, wind, and pressure, from weather stations, balloons, and satellites all over the world, then feed all of it into powerful computer programs that simulate how the atmosphere is likely to behave next. These computer models are not perfect, so meteorologists also compare several different models and use their own experience to judge which prediction looks most likely. Forecasts tend to be quite accurate for tomorrow but get less certain the further ahead they try to look.