Video narration
Why does a cyclone bring rain-is it simply because the storm is spinning? Think of droplets forming on a cold glass. Moist air cools, and invisible water vapour changes into tiny liquid drops. That change is condensation. A cyclone has low pressure: air pressure is lower there than around it. Moist air moves inward and rises. Here is the important turn: spinning does not directly make rain. Rising air does. As air rises, it expands and cools. Water vapour condenses into cloud droplets. When droplets become heavy enough, they fall as rain. Because a cyclone draws moist air across a broad area and keeps lifting it, rainfall can be widespread and intense. So cyclonic rainfall comes from low pressure lifting moist air, not spinning alone. The air cools, condensation forms clouds, and rain falls. The lifting and cooling-not the spin-is what drives the rain.