Cyclone Nisarga

Why in news?

India will face Cyclone Nisarga on its western coast soon.

When will it be known as Cyclone Nisarga?

• After the powerful Cyclone Amphan that struck the eastern coast on May 20, 2020, India is bracing to face another cyclone.
• It is not even a full-fledged cyclone right now, just a ‘depression’.
• This depression is likely to intensify into a ‘deep depression’ soon, and eventually into a cyclone, after which it would be called Nisarga.
• In strength and intensity, Cyclone Nisarga would be much weaker than Cyclone Amphan.

Where is it headed?                                                                               

• It is headed towards the coastline of north Maharashtra and south Gujarat.
• It may hit the coastline on June 3, between Harihareshwar in Raigad district, just south of Mumbai, and Daman, just below Gujarat coast.
• By that time, it is likely to evolve into a Severe Cyclonic Storm.
• This storm, roughly stated, will be of strength 2 on a 1-to-5 of strength of cyclones that arise in the Indian Ocean.

What does that mean?

• The cyclones’ strength is measured by the wind speeds they generate.
• At its strongest, Nisarga would be associated with wind speeds in the range 95-105 km per hour.
• Amphan was classified as a super-cyclone of category 5.
• But Amphan had weakened to category 4, ‘Extremely Severe Cyclonic Storm’, ahead of its landfall, at which time the wind speeds were in excess of 180 kph.
• Cyclones formed in the Bay of Bengal side of the Indian Ocean are more frequent and stronger than those on the Arabian Sea side.
• The relatively cold waters of the Arabian Sea discourage the kind of very strong cyclones that are formed on the Bay of Bengal side.
• Odisha and Andhra Pradesh face the brunt of these cyclones every year.
• However, according to India Meteorological Department, in 2019, the Arabian Sea saw the most frequent and intense cyclonic activity in more than 100 years.
• Five cyclones originated in the area in 2019 - Vayu, Hikka, Kyarr, Maha and Pavan - when normally only one or two are formed.

So how big is the threat?

• If the system does intensify into a cyclonic storm, some coastal districts of Maharashtra will come directly in line of its predicted path.
• Though the exact location of the landfall is still to be determined, it is likely to be close to Mumbai.
• Neighbouring Thane, Raigad, Ratnagiri and Sindhudurg are also likely to be affected.
• Heavy to very heavy rainfall is predicted in these areas until June 4.
• The southwest monsoon has already made an onset over Kerala.
• There is an associated depression lying parallel to the west coast, which is intensifying, and moving northwards along the coast.
• Under such circumstances, the east-central and southeast regions of Arabian Sea are already experiencing rough weather conditions.
• These weather conditions are likely to get intensified because of this cyclone.

Would Maharashtra get early monsoon rainfall?

• No, the rainfall over the next three days in Maharashtra would not be due to the southwest monsoon, which is still to begin its northward movement from Kerala.
• Normally, monsoon arrives over Maharashtra after June 10, 2020.

Source: The Indian Express