Cyclone 'Remal' to make landfall near Bengal on May 26; to bring rains, thunderstorms to Tamil Nadu: IMD

CHENNAI: The Indian Meteorological Department (IMD) has announced that the first cyclone in the Bay of Bengal this pre-monsoon season will make its landfall near West Bengal on the evening of May 26. It has been named 'Remal', meaning sand in Arabic.

The existing low-pressure system over the Bay of Bengal will concentrate into a depression over central Bay of Bengal by Friday morning. It will further intensify into a cyclonic storm on Saturday morning and reach Bangladesh and the adjoining West Bengal coast as a severe cyclonic storm by Sunday evening, the IMD said.

According to the IMD, the cyclone could reach a wind speed of 102 kilometres per hour on Sunday.

As a result, there is a possibility of rain with thunder and lightning in a couple of places in Puducherry and Karaikal on Thursday and Friday, with the likelihood of continuous rain accompanied by thunder from May 25.

It is expected that rains may decrease in Tamil Nadu and temperatures may increase as the storm moves toward the north.

Meanwhile, the Met office has warned of very heavy rainfall in the coastal districts of West Bengal, north Odisha, Mizoram, Tripura and south Manipur on between May 25 and 27. Fisherfolk out at sea have been advised to return to the coast before May 23, and not venture into the Bay of Bengal until May 27.

ALSO READ: Fifteen rain-related deaths reported across Tamil Nadu between May 16 and 22

Cyclone named 'Remal'

The World Meteorological Organization (WMO) decided in 2020 to prepare a list of names for tropical cyclones that occur in the Arabian Sea and the Bay of Bengal, which together are referred to as the North Indian Ocean. The IMD had presented a list of 169 names for cyclones that year. They had suggested that if the current cyclonic circulation in the Bay of Bengal intensifies into a cyclone, it will be named 'Remal'.

Wind warning:

The weather department has forecast squally weather with wind speed reaching 35-45 kmph gusting to 55 kmph over south Bay of Bengal on May 22.

It would gradually increase to 40-50 kmph gusting to 60 kmph over central and adjoining South Bay of Bengal from May 23 morning. It would later extend to adjoining areas of North Bay of Bengal with an increased wind speed of 50-60 kmph and later 70 kmph on May 24 morning, and over the northeast Bay of Bengal and adjoining northwest and east-central Bay of Bengal from May 25 morning till 26 evening.

Sea condition

The sea condition is likely to be moderate to rough over the southwest Bay of Bengal on May 22, rough to very rough over the central and adjoining south Bay of Bengal from May 23, and over the North Bay of Bengal from May 24 onwards till May 26.

Warning for fishermen

Fishermen are advised not to venture into the central and adjoining south Bay of Bengal from May 23 and into the North Bay of Bengal from May 24 to 26. Fishermen out at sea are advised to return to the coast before May 23.

READ MORE: Heavy rains lash Kerala, IMD issues red alert in two districts

Why are cyclonic storms intensifying rapidly?

Scientists say cyclonic storms are intensifying rapidly and retaining their potency for longer periods due to warmer sea surface temperatures, a result of oceans absorbing most of the excess heat from greenhouse gas emissions.

The past 30 years have witnessed the highest sea surface temperatures since records began in 1880.

According to senior IMD scientist DS Pai, warmer sea surface temperatures mean more moisture, which is favourable for the intensification of cyclones.

Madhavan Rajeevan, former secretary of the Union Ministry of Earth Sciences, said a sea surface temperature of 27 degrees Celsius and above is needed for a low-pressure system to intensify into a cyclone. The sea surface temperature in the Bay of Bengal is around 30 degrees Celsius at present.

"The Bay of Bengal and the Arabian Sea are very warm at present, so a tropical cyclone can easily form," Rajeevan said.

But tropical cyclones are not only controlled by the ocean; the atmosphere also plays an important role, especially in terms of vertical wind shear -- a change in wind speed and/or wind direction with altitude.

"A cyclone will not intensify if the vertical wind shear is very large. It will weaken," Rajeevan said.

Models suggest the cyclone will not affect the monsoon progress, the senior meteorologist said.

Pai, however, said it could affect the progress of the monsoon in some parts.

He told PTI, "Initially, the system will help the monsoon progress over the Bay of Bengal. Thereafter, it will detach from the monsoon circulation and pull a lot of moisture, which could result in a slight delay in the monsoon progress in that area."

(With PTI inputs)