New Andaman Sea weather system to bring heavy rain to southern TN

Rainfall Likely In Northern Districts Too From Dec 1

U.Tejonmayam@timesgroup.com

Chennai:29.11.2020

Less than a week after very severe cyclonic storm Nivar made landfall near Marakkanam dumping vast amounts of rain, another weather system is on its way to the TN coast.

Weathermen said a low pressure area has formed over south Andaman Sea and is likely to move towards south Tamil Nadu after intensifying into a depression, bringing widespread rainfall from December 1. Extremely heavy rainfall can be expected in some parts of southern districts of TN, which have recorded a deficit so far since October 1, while northern districts, including Chennai, may receive heavy spells of rain. In its bulletin, IMD said the low pressure area has formed over south Andaman sea and adjoining areas of southeast Bay of Bengal and east equatorial Indian Ocean on Saturday. “It is very likely to move west-northwestwards and reach south Tamil Nadu coast on December 2,” the agency said.

Private weather forecasters said the system is likely to cross the Gulf of Mannar and Comorin Area before moving into the Arabian Sea.

Centre constitutes eight-member team, 10,000 hectares of crop damaged in TN

The Centre has constituted an eight-member interministerial team, led by home ministry joint secretary Ashutosh Agnihotri, to assess the damage caused by cyclone Nivar in Tamil Nadu and Puducherry. TN government has estimated that around 9,687 hectares of agricultural and horticultural crop had been damaged by the storm, including 5,950 hectares of fullygrown paddy crop in Cuddalore, Kancheepuram, Chengalpet and Tiruvannamalai districts. While six people died due to wall collapse, falling of trees and heavy rain in Chennai, Tiruvarur, and Villupuram, seven people were injured. According to the latest TN estimate, 605 houses, including 2,313, were damaged, and 264 cattle and 5,107 poultry died. P 10

‘At most, system may become a deep depression near TN coast’

Weather bloggers said it may turn into a weak cyclone over theArabian Sea far awayfrom the Indian coast before moving towards Somalia or Oman.

IMD forecast “heavy to very heavy rain at a few places with isolated extremely heavy spellsover southTN andsouth Kerala on December 2 and isolated heavy to very heavy rain over these regions on December 1and 3. Over north TN, Puducherry, Mahe and Karaikal and north Kerala, heavy to very heavy rain islikely from December 1to3”.

On November 30, Gulf of Mannar region could experience increased wind speeds of 45-55kmph gusting to 65 kmph and by December 1, it could 65-75kmph gusting to 85kmph along and off south TN coast and 50-60kmph gusting to 70kmph along and off north TN, Puducherry and Kerala coast, Comorin area and Gulf of Mannar. By December 2, wind could increase to 70-80kmph gusting to 90kmph along and off south TN and Kerala coasts, Comorin area and Gulf of Mannar. North TN and Puducherry coast as well as north Kerala coast could see winds at 55-65kmph gusting to 75kmph.

Weather blogger Pradeep John said Chennai will receive convective rain from wind convergence caused by the system pulling the easterliesintotheland asit nearsthe TN coast and from the cloud bands around it. “South, southwest and delta regions, including Kanyakumari, Ramanathapuram and Tenkasi which have recorded a deficit so far this season, will receive very heavy spells...,” he said.

Weather watchers said the system could, at the most, intensify into a deep depression when it is near the TN coast. But a global climate phenomena like Madden-Julian Oscillation, an eastward moving disturbance of clouds, rainfall, winds and pressure which is now in the Indian Ocean, and a warm sea surface temperature will add strength to it.

Though there was an upwelling of the sea when Cyclone Nivar crossed, Mahesh Palawat, chief meteorologist, Skymet Weather, said the sea surface temperatures are warmer at 28-29 deg C. “But thissystem willbefast moving and won’t spend much time over the sea to intensify. Any system requires to travel at least five to six days over the sea to gather moisture and strengthen into a cyclonic storm,” he said. Further, climate studies have shown that many weather systems that originated from the Andaman Sea had goneon tointensify into cyclonic storms.

Soon after this system nears TN, forecasters, said another system may form over the same region of south Andaman Sea by December 8/9. So far, global weather models show that this system may intensify into a cyclonic storm, compact and strong, and is likely to move closer to Ch