Asani to intensify into ‘severe’ cyclonic storm today; Odisha, Bengal on alert
- According to Indian Meterological Department, Cyclone Asani, which developed over southeast regions of Bay of Bengal, will intensify into a ‘severe cyclone’ by Monday.
- The storm will reach close to the Andhra Pradesh-Odisha coast by Tuesday.
- It is unlikely to make a landfall and it could skirt the coastal districts of these states in the next two days.
Intensity of cyclone
- If realised, cyclone Asani could have similarities like cyclone Jawad that developed in the Bay of Bengal and swerved past close to south Odisha in December last year.
- Cyclone Asani rapidly intensified while at sea over the past two days.
- The storm had intensified into the ‘severe’ category after moving at a speed of 14 km per hour.
- 610 km northwest of Car Nicobar
- 500 km west of Port Blair
- 810 km southeast of Visakhapatnam
- 880 km south-southeast of Puri.
- It is very likely to continue to move northwestwards till Tuesday evening and reach west-central and adjoining Northwest Bay of Bengal region, off north Andhra Pradesh and Odisha coasts by Tuesday.
- Odisha has been put on a high alert ahead of the heavy rain (64.4mm to 115.5mm in 24 hours) forecast on Tuesday and Wednesday.
- Under the influence of the system in the Bay of Bengal, thunderstorms, lightning and light rain is forecast over Bihar, Jharkhand, West Bengal and Sikkim till May 12.
- Tropical cyclones are violent storms that originate over oceans in tropical areas and move over to the coastal areas bringing about large-scale destruction due to violent winds (squalls), very heavy rainfall (torrential rainfall), and storm surge.
- They are irregular wind movements involving the closed circulation of air around a low-pressure center.
- This closed air circulation (whirling motion) is a result of rapid upward movement of the hot air which is subjected to Coriolis force.
- The low pressure at the center is responsible for the wind speeds.
- The cyclonic wind movements are anti-clockwise in the northern hemisphere and clockwise in the southern hemisphere (This is due to Coriolis force).
- The cyclones are often characterized by the existence of an anticyclone between two cyclones.
- Tropical cyclones occur around the equator at 5 ° – 30 °, but also have varying names depending upon where in the world they form.
- An average tropical cyclone can travel about 300 to 400 miles a day, or about 3,000 miles before it dies out.
Conditions Favorable for Tropical Cyclone Formation
- Large sea surface with a temperature higher than 27° C,
- Presence of the Coriolis force enough to create a cyclonic vortex,
- Small variations in the vertical wind speed,
- A pre-existing weak low-pressure area or low-level-cyclonic circulation,
- Upper divergence above the sea level system,
Why cyclones occur mostly in late summers?
- Whirling motion is enhanced when the doldrums (region within ITCZ) over oceans are farthest from the equator.
- This happens during the autumnal equinox (August-September).
- At this time, there are two advantages—the air is overheated and the sun is exactly over the equator.
- Cyclone formation
- Naming of cyclone
Q. What do you understand by tropical cyclones and how are they formed? Also examine the impact of these cyclones on India. (250 words)