Cyclonic winds in Bay of Bengal delay withdrawal of SW monsoon

Cyclonic circulations in the Bay of Bengal have delayed the withdrawal of the southwest monsoon this year, an India Meteorological Department (IMD) official said here Tuesday.

The withdrawal of the southwest monsoon is now expected to begin from September 29, a delay of four days compared to the last year.

"The southwest monsoon was excepted to show indicators of its withdrawal in the last week (September 16-22) but cyclonic circulations in the Bay of Bengal delayed its movement," the official said.

In IMD parlance, a cyclonic circulation is the atmospheric wind flow in upper levels associated with any low pressure system. The wind flow is counter clockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.

Going by the dry air and clear skies, the monsoon withdrawal is expected to start from Saturday (Sept 29), he said.

"The similar indicators were shown on September 25 last year. This year, there is a delay of four days," according to the official.

The departing monsoon typically brings rainfall in arid regions which benefits the rabi crops in the country.

The arid Marathwada region in central Maharashtra generally receives good showers during this period, the official said.

"The southwest monsoon had reached Kerala two days prior to its date of arrival, but covered Maharashtra after 10 days, as against the normal period of seven days. The monsoon had covered the entire Maharashtra by June 8 when normally it reaches Mumbai by June 7," the official said.

He said the strong winds had pushed the monsoon hard and by July 29 the entire country was covered.

"This time, intensity of showers was quite high. Instead of spreading the showers into days, the one-time precipitation was quite higher," the official said.

The exact data of rainy days in the country is being compiled, but it is going to be less than the normal, he said.

"However, we have received rainfall which is close to the normal," he explained.