Context: Atlantic hurricane Nana has made landfall on the coast of Belize and is expected to weaken as it moves over land, the U.S. National Hurricane Center (NHC) said in its latest advisory.

• Nana, packing maximum sustained winds of 75 miles (120 km) per hour, is located about 50 miles (80 km) south of Belize City.
• 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).

Key Points
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.

Formation

• 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.

Features

• 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