1. Cyclones form over warm ocean waters above 25°C and require specific conditions including low pressure, rising air, and counterclockwise rotation in the Northern Hemisphere. 2. Cyclones can cause strong winds over 150 kph, large waves, flooding from heavy rain, and damage from blown down buildings. 3. The primary effects are immediate damage from high winds, flooding, and storm surge while secondary effects later include disease, starvation, and loss of income from destroyed crops and infrastructure.