TROPICAL CYCLONES WHAT IS A TROPICAL CYCLONE? Tropical cyclones are intense circular storms that originate over warm tropical oceans. They are characterised by low atmospheric pressure, high winds and heavy rain. WHERE AND HOW IS A TROPICAL CYCLONE FORMED? • Tropical cyclones form over warm areas of the Atlantic, Pacific and Indian oceans. • They obtain their energy from warmth and moisture that rises from the ocean surface. • A tropical storm develops once the wind speed reaches 63 kilometres per hour. • When wind speeds are more than 119 kilometres per hour, the tropical storm becomes a cyclone. • High-speed winds move in a spiral around a calm centre, called the eye (an area of low pressure with clear skies). • The wall of clouds surrounding the eye bring strong winds and heavy rain. • When the storm passes over colder waters or large land areas it will lose its source of energy and the storm will die. For more information on being Water Wise please contact 0860 10 10 60 or log onto www.randwater.co.za and click on the Water Wise logo #WaterWise #RandWater #KnowBetterDoBetter Credit: www.britannica.com/science/tropical-cyclone Credit: https://www.britannica.com/science/tropical-cyclone TROPICAL CYCLONES HOW ARE TROPICAL CYCLONES TRACKED? TROPICAL CYCLONE INTERESTING FACTS Meteorologists develop modern techniques such as numerical • Tropical cyclones are also called hurricanes or typhoons depending weather prediction models to forecast how a tropical cyclone on the regional location (Hurricane: Atlantic or Eastern Pacific evolves. These models include tracking its movement and Oceans; Typhoon: Western North Pacific and Philippines; Tropical change of intensity, when and where one will hit the land and Cyclone: Indian and South Pacific). at what speed. Official warnings are then issued by the • Winds blow counter clockwise in the northern hemisphere and National Meteorological Services. clockwise in the southern hemisphere. • Tropical cyclones with a certain strength are given names in the DANGERS OF TROPICAL CYCLONES interests of public safety and identification. They are very dangerous to houses and people as they cause severe damage to human life and activities. Tropical cyclones bring violent winds, torrential rain, high waves and, in some cases very destructive storm surges and coastal flooding. Recently tropical cyclone Eloise hit Mozambique and parts of South Africa, such as Kwazulu-Natal, Mpumalanga and Limpopo, and did much damage. The South African Weather Services issued a warning that there would be heavy rain as a result of this tropical cyclone. Unfortunately people still drove through flooded areas and bridges and people drowned. Respect the warning signs by government and other entities as life of an individual cannot be replaced. We need to appreciate tropical cyclones as part of Earth’s natural processes. Cyclones like Eloise contributed to the filling of dams in South Africa. RESPECT WATER, RESPECT LIFE! For more information on being Water Wise please contact 0860 10 10 60 or log onto www.randwater.co.za and click on the Water Wise logo #WaterWise #RandWater #KnowBetterDoBetter Photo Credits: www.theguardian.com; www.news24.com; www.sandtonchronicle.co.za and www.sabcnews.com YOUR FEEDBACK It would be most appreciated if you could please give feedback on this education material by clicking on the following link: https://forms.gle/ePtXdPBUjTz4Um5H7 For more information on being Water Wise please contact 0860 10 10 60 or log onto www.randwater.co.za and click on the Water Wise logo #WaterWise #RandWater #KnowBetterDoBetter.