Cyclonic storm is caused by atmospheric disturbances around a low-pressure area and is usually accompanied by violent storms and severe weather conditions. Cyclone is derived from the greek word cyclos – coiling of snake. Tropical Cyclone is a deep low pressure area from around the center the strong winds, spirals and pick up the speeds of 62 kmph or more. In Northern hemisphere these winds rotate counter clock wise and in Southern hemisphere clockwise. The tropical cyclones that are intense are known as huricanes Over the Atlantic Ocean and typhoons over the pacific ocean. They are know by different names for example dust devils, supercell thunderstorm, tomadoes, tropical cyclones, extra tropical cyclones etc. On the basis of the speed of the wind cyclones are classified into 5 different categories.
According to the category of the cyclone the wind speed varies that is from 60 km an hour to about 220 kmph and above. When the speed of the wind around the low pressure area reach upto 60 kmph it is known as tropical cyclone and the name is assigned. When wind speed settles between 89 and 118 kmph, it turns into a severe Cyclonic storm. When wind blows at a speed of about 119 to 221 kmph then it is known as very severe Cyclonic storm and when the speed of the wind exceeds 221kmph then the cyclone is known as supercyclonic storm. The word meteorological organization (WMO) has a well defined process to select the name of each cyclone.
A cyclone named fani is a massive Cyclonic formation over the south of bay of Bengal which made landfall in odisha.
Cyclone like ookhi hit parts of kerala, tamil nadu, sri lanka, and maldives at 185kmph with total fatalities of 245 in kerala that time around 80 fisherman were killed and 140 people were reported missing. In 2018 cyclone gaja also made landfall in Nagapattinam ‘s vedaranyam block and killed around 46 people. In 2019 vayu in the Arabian Sea.
The polar vortex is a large area of low pressure and cold air surrounding the Earth’s North and South poles in each Hemisphere. The term refers to the counter clockwise flow of air that helps the colder air close to the poles. Often during winter in the Northern hemisphere the polar vortex will become less stable and expand senting cold artic air southward over the East of US with the jet stream. One exist in the troposphere where we live and where the weather happens. The other exists in the second lowest, called the stratosphere, which is a shroud of thin air that gets warmer at higher altitudes. The tropospheric polar vortex is the one that affects our weather with piercing shots of cold, intense bouts of storminous and bitter wind chills reaching upto 80°Celsius.