- 04 Sep 2020
- 3 min read
Why in News
Atlantic Hurricane Nana has made a landfall on the coast of Belize.
- The country Belize is located on the northeast coast of Central America.
- Few days back, Hurricane Laura made landfall in southwestern Louisiana (South Central United States).
- Tropical Cyclone:
- A hurricane is a type of storm called a tropical cyclone, which forms over tropical or subtropical waters.
- A tropical cyclone is a rotating low-pressure weather system that has organized thunderstorms but no fronts (a boundary separating two air masses of different densities).
- Speed of Winds:
- Tropical cyclones with maximum sustained surface winds of less than 39 miles per hour (mph) are called tropical depressions.
- Those with maximum sustained winds of 39 mph or higher are called tropical storms.
- When a storm's maximum sustained winds reach 74 mph, it is called a hurricane.
- Measurement of Wind Speed:
- The Saffir-Simpson Hurricane Wind Scale is a 1 to 5 rating, or category, based on a hurricane's maximum sustained winds.
- The higher the category, the greater the hurricane's potential for property damage.
- There needs to be warm ocean water and moist, humid air in the region.
- When humid air is flowing upward at a zone of low pressure over warm ocean water, the water is released from the air as creating the clouds of the storm.
- It has a low pressure centre and clouds spiraling towards the eyewall surrounding the "eye", the central part of the system where the weather is normally calm and free of clouds.
- Its diameter is typically around 200 to 500 km, but can reach 1000 km.
- The winds blow counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.
- A tropical cyclone brings very violent winds, torrential rain, high waves and, in some cases, very destructive storm surges and coastal flooding.
- Different Names:
- Hurricane: Caribbean Sea, Gulf of Mexico, North Atlantic Ocean and the eastern and central North Pacific Ocean
- Typhoon: Western North Pacific
- Cyclone: Bay of Bengal and Arabian Sea
- Willy-willies: Australia