Cyclone Remal to reach West Bengal, Bangladesh coasts by Sunday evening, says IMD | Key points

The India Meteorological Department (IMD) told news agency PTI on Thursday that a low-pressure system over the Bay of Bengal will intensify and reach Bangladesh and adjoining West Bengal coasts as a severe cyclonic storm by Sunday evening.

It is the first pre-monsoon cyclone in the Bay of Bengal and will be named Remal, according to a system of naming cyclones in the Indian Ocean region.

IMD scientist Monica Sharma told PTI that the cyclonic system will concentrate into a depression over the 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." 

Also read: Rainfall lashes Kolkata, more showers expected in THESE districts of Bengal and Odisha till May 26

Here are some key points about Cyclone Remal:

• According to IMD, the cyclone is likely to reach a wind speed of 102 kilometres per hour on Sunday.
• Warned of very heavy rainfall in the coastal districts of West Bengal, north Odisha, Mizoram, Tripura and south Manipur on May 26-27 has been issued.
• Fishermen have been advised to return to the coast and not venture into the Bay of Bengal until May 27.

Also read: IMD issues advisory for fishermen amid ‘very heavy rainfall’ predictions

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

Also read: Kerala rains: 7 die after heavy rainfall, IMD issues red and orange alert

• Former secretary of the Union Ministry of Earth Sciences, Madhavan Rajeevan, 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." 
• 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.

Also read: Heatwave alert! IMD issues red alert for Rajasthan, Punjab, Haryana, Delhi, and Uttar Pradesh

• "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," Pai told PTI.