india

Updated: Jan 10, 2020 07:57 IST

Northeast monsoon rains are likely to cease over peninsular India from Friday, India Meteorological Department (IMD) said on Thursday. The peninsular region received normal rains this year at 109% of the long period average (LPA) after two years of deficient rains. Last year, the southern peninsula had received only 66% of the LPA and 86.1% in 2017.

A positive Indian Ocean Dipole (IOD) in 2019 led to good rains over the core northeast monsoon region, meteorologists said.

IOD is characterised by warmer sea surface temperatures in the equatorial Indian Ocean. Positive IOD conditions are associated with normal monsoon. The overall rainfall in the entire country in the post-monsoon season (October to December) was considerably above normal at 129% of the LPA compared to 56% in 2018.

“It is the positive IOD, more low-pressure systems moving from the Bay of Bengal to the Arabian Sea, which brought good rains to south India. In 2015 also we got very good rains in the post-monsoon season. There were floods in Chennai during the northeast monsoon season. It was also an El Nino year,” said DS Pai, a senior scientist at IMD Pune.

During the south-west monsoon season (June to September) in 2019, rainfall was above average at 110% of the LPA. Central India and South Peninsular India received 129% and 116% of its LPA rainfall respectively during the summer monsoon season.

There was a delay in the onset of south-west monsoon and very little rain in June due to the presence of a weak El Nino. The month ended with a 33% deficit in rainfall. The summer monsoon was also prolonged by 39 days . The IMD had officially announced the withdrawal of monsoon on September 30 but rains continued, contributing to excessive rains in the post-monsoon season.

“We could not announce the cessation of the NE [Northeast] monsoon because it has been raining till now in the peninsular region. Rains have to stop completely for us to announce a cessation,” said K Sathi Devi, head of National Weather Forecasting Centre.

A fresh Western Disturbance is very likely to affect western Himalayan region from January 11 onwards. “An induced cyclonic circulation is also very likely to form over West Rajasthan and neighbourhood on 13th January. Under its influence, fairly widespread to widespread precipitation is very likely to occur over Western Himalayan region mainly on January 12 and 13 with the possibility of isolated heavy fall over Jammu and Kashmir on January 12 and 13 and over Himachal Pradesh on January 13,” an IMD bulletin said.