Monsoon exit to start anytime in two weeks

PUNE: Monsoon may miss its official September 1 date of exit from the extreme west Rajasthan, but weather models hinted at its withdrawal anytime in the next two weeks.
A source in the India Meteorological Department (IMD) department said there were indications of monsoon withdrawal beginning after September 6 but cautioned that it was still early to make a sweeping statement because monitoring of the conditions was required during that time. Private forecaster Skymet Weather Services said the withdrawal could begin in the first week of September because most conditions, except southwesterly wind flow, seem to have surfaced to trigger a withdrawal from the region soon.

The monsoon withdrawal begins from the west Rajasthan region. Cessation of rainfall activity for five days on the trot is one of the criteria for the first monsoon withdrawal from the western parts of northwest India.

An IMD official told TOI that the models were currently showing decreasing rainfall after the first week of September. “As of now, there are indications that monsoon withdrawal may begin from the extreme parts of northwest India during the second week, but the withdrawal cannot be declared in haste. One has to keep in mind the spatial continuity during the process,” he said.

The official based his reasons on what happened last year. “In 2017, monsoon suddenly revived during the third week of September with good rainfall around September 20, which pushed the withdrawal to September 27. As of now, it is too early to forecast rainfall conditions around mid-September,” he said.

Chief meteorologist of Skymet Weather Services Mahesh Palawat told TOI that September 1 was the normal date for monsoon withdrawal to begin from the extreme west of northwest India. “During withdrawal, an anti-cyclone forms over central Pakistan and adjoining Rajasthan, and northwesterly or dry winds begin blowing over parts of northwest India. This anti-cyclone restricts the movement of any weather system towards the central India from the Bay of Bengal. As of now, an anticyclone may form around the first week of September, after which monsoon may start withdrawing from western parts of Rajasthan and parts of northwest India,” he said.

According to the IMD’s weather models, the monsoon rainfall may be mainly concentrated over eastern parts of north India, adjoining central India and eastern India, with normal to above-normal rainfall over Madhya Pradesh, east Rajasthan, UP Bihar, Jharkhand, Uttarakhand, adjoining Himachal Pradesh, north Chhattisgarh, north Odisha, Gangetic West Bengal and parts of northeast India during the period from August 31 to September 6.

Deficient or below-normal rainfall may occur over northwest India, western coastal regions of India and south peninsular India During this period.