A south-west Indian Ocean tropical cyclone is like a big windy and rainy storm that happens in the ocean near Africa.
Think of it like a giant spinning top - the top part is where the wind and rain is the strongest and it moves around in circles.
These storms can be very strong and cause a lot of damage to homes and buildings. People who live near the coast need to make sure they stay safe and have supplies to last through the storm.
Scientists and weather experts keep track of these storms and try to predict where they will go so that people can prepare and stay safe.