This October has turned out to be the fifth driest in the city in the last 200 years. Weathermen are attributing the deficiency in rainfall to several factors, including typhoons Sarika and Haima in the South China Sea and Cyclone Kyant over the Bay of Bengal, that delayed the onset of the northeast monsoon over the southern peninsula.
"Due to the cyclonic activity in the South China Sea, dry westerly winds continued to prevail in October," says weather blogger Pradeep John. In the later part of the month, Cyclone Kyant formed over the Bay of Bengal and moved northeastwards to Myanmar before returning to the Andhra coast as a low-pressure area. "As Cyclone Kyant was active near Myanmar, there was no activity over the TN coast. The cyclone delayed the easterly winds by a further 10 days," John said.
Usually, the northeast monsoon is expected to arrive around October 20. In 2015, when Chennai received record rainfall, the northeast monsoon had set in on October 28, while this year it commenced on October 30. As 2015 was an El Nino year, excess rainfall was expected. Neutral to weak La Nina conditions has been forecast this year, indicating below normal rainfall.
Heavy rainfall as a result of a cyclone could erase the deficit in a matter of days and weathermen remain hopeful. As per IMD's forecast, there is an upper air cyclonic circulation over the south Andaman Sea which can lead to the formation of a low-pressure area over the Bay of Bengal.
"The upper air circulation will most likely develop into a cyclone. It will take a few days to predict whether it will make landfall near Tamil Nadu or move away towards the Andhra Pradesh coast," said John. Skymet Weather chief meteorologist Mahesh Palawat, however, suggests that the cyclonic formation, which can bring heavy rainfall, will be near the Andhra and Orissa coast.
"As the cyclonic circulation moves away from the Tamil Nadu coast, it will take away moisture-laden winds, leaving the state high and dry," Palawat said. There will be scattered rainfall over TN until November 3, following which there will be a dry spell for about a week, he predicted.
"Due to the cyclonic activity in the South China Sea, dry westerly winds continued to prevail in October," says weather blogger Pradeep John. In the later part of the month, Cyclone Kyant formed over the Bay of Bengal and moved northeastwards to Myanmar before returning to the Andhra coast as a low-pressure area. "As Cyclone Kyant was active near Myanmar, there was no activity over the TN coast. The cyclone delayed the easterly winds by a further 10 days," John said.
Usually, the northeast monsoon is expected to arrive around October 20. In 2015, when Chennai received record rainfall, the northeast monsoon had set in on October 28, while this year it commenced on October 30. As 2015 was an El Nino year, excess rainfall was expected. Neutral to weak La Nina conditions has been forecast this year, indicating below normal rainfall.
Heavy rainfall as a result of a cyclone could erase the deficit in a matter of days and weathermen remain hopeful. As per IMD's forecast, there is an upper air cyclonic circulation over the south Andaman Sea which can lead to the formation of a low-pressure area over the Bay of Bengal.
"The upper air circulation will most likely develop into a cyclone. It will take a few days to predict whether it will make landfall near Tamil Nadu or move away towards the Andhra Pradesh coast," said John. Skymet Weather chief meteorologist Mahesh Palawat, however, suggests that the cyclonic formation, which can bring heavy rainfall, will be near the Andhra and Orissa coast.
"As the cyclonic circulation moves away from the Tamil Nadu coast, it will take away moisture-laden winds, leaving the state high and dry," Palawat said. There will be scattered rainfall over TN until November 3, following which there will be a dry spell for about a week, he predicted.