Most of the low pressure areas are formed in the Bay of Bengal or the Arabian sea, but some have their roots elsewhere. Credit: Getty Images
Cyclone Gaja has intensified into a severe cyclonic storm and currently lies very close to the Tamil Nadu coast. It will make landfall in the evening today, says the India Meteorological Department’s (IMD) latest forecast.
On November 13, it had changed its track to move towards southern Tamil Nadu rather than the north. More of such changes would mean damages in regions which are not prepared.
The cyclonic storm is forecasted to decrease in intensity and make landfall between the towns of Cuddalore and Pamban with wind speeds of 80-90 km/hr. Post the landfall, it will retain its cyclonic characteristics and will have wind speeds of up to 70 km/hr on land for six hours.
This is the first cyclone to move towards Tamil Nadu this year. The earlier two named Daye and Titli had made landfall along the Odisha coasts, brought heavy rainfall and damaged the coastal districts of Odisha and Andhra Pradesh.
All cyclones begin as low pressure areas over the ocean surface and then intensify into depressions, deep depressions, cyclones, severe cyclones and very severe cyclones based on their wind speeds.
In this year, 13 depressions have already formed over the Bay of Bengal and the Arabian Sea. This is the highest number of depressions in the region in the past 26 years, according to data from the IMD. The last time 13 depressions were formed in a single year in the North Indian Ocean was in 1992. With the season of depressions still not over, this record might yet be broken.
Though most of the low pressure areas are formed in the Bay of Bengal or the Arabian sea, some have their roots elsewhere. Gaja is one such cyclone.
“Usually, such cyclones are formed when remnants of typhoons from the Pacific Ocean come into the Indian Ocean or the Bay of Bengal and re-intensify into cyclones when they find warm ocean waters in these regions. The track of the cyclone is also usually directed towards North Tamil Nadu in the initial stages”, P Mukhopadhyay, a senior scientist at the Indian Institute of Tropical Meteorology (IITM), Pune told Down to Earth.
Cyclone Gaja could have formed from a remnant of Supertyphoon Yutu, which had devastated the Philippines in the last week of October.
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