Cyclone Ashobaa slows monsoon progress in India

El Nino is expected to cause further disruptions to rainfall patterns this year

Published: Thursday 11 June 2015

Progress of monsoon, as shown in a map released by India Meteorological Department (IMD)

The deep depression over the Arabian Sea that intensified into cyclonic storm Ashobaa is expected to further develop into a super cyclonic storm. The cyclone is expected to make a landfall in Oman’s east coast.

Even as the storm has moved away from the India’s west coast, heavy winds and isolated showers have been reported in parts of Gujarat, Konkan region of Goa and Karnataka. While the depression has brought rainfall in some regions, its impact on the southwest monsoon winds has delayed the advance of India’s monsoon.

Traditionally, as lands in north and central India heat up, a low pressure area is formed over these regions. Moisture-rich winds from the Indian Ocean then sweep across the subcontinent to fill the low-pressure void. It is these winds that form the cloud cover and usher in the monsoon. This year, unseasonal rains have delayed the formation of the low pressure system over north and central India and the advance of moisture-laden winds from the Indian Ocean.

What causes disruption?

While Kerala’s monsoon onset was delayed by a few days and hit the state on June 5, the Ashobaa cyclonic depression over the Arabian Sea has disrupted the normal flow of the southwest monsoon winds. Therefore, the southwest monsoon winds have now turned towards the north and the west after entering the Southern Peninsula. The southwest monsoon winds have entered east and northeast India and have been active over the last 48 hours. Heavy rains have already been reported in Arunachal Pradesh, Assam and Meghalaya.

Latest satellite images show convective or rain creating clouds off the southwestern coast and over the northeastern region. Despite the delays, Brahma Prakash Yadav, scientist at India Meteorological Department (IMD) is optimistic about the progression of the rain clouds. “The delays we have seen are nothing major, the cyclonic depression is bound to have some impact but this is not very large. We expect the monsoon to get back to normal within a day or two once cyclone Ashobaa achieves landfall and wind disturbances abate,” he says.

El Niño fears remain

The monsoon has already suffered a setback with the confirmation and subsequent intensification of El Niño. This year, the El Niño pattern might even be reminiscent of the 1997-98 event which is the strongest El Niño recorded. In its recent forecast, IMD had said that there was a well-established El Nino this year. The weather agency had also revised the forecast for the Indian monsoon down from 93 per cent to 88 per cent (±4 per cent), sparking fears of deficient rainfall over the mainland.

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