Heavy monsoon rains return to northwest India

Widespread rainfall has been reported from northwest India, east India and along the west coast during the 24 hours ending Friday morning helping retain the overall deficit at five percent from overnight.

An India Meteorological Department (IMD) said in the evening update that the axis of the monsoon has generally reverted to the normal position.

BROKEN TROUGH

But interestingly, the monsoon trough had broken up into two – one dry-docked with its eastern end running through land into Mizoram and the other one passed through Allahabad, Pandra, Jagdalpur, Kakinada and then south-eastwards to dip into southeast Bay of Bengal.

The trough continues to be vulnerable to lateral movement during the next two to three days, the IMD said.

Meanwhile, an ex-typhoon and now a tropical storm, Nock-Ten, was preparing to wash over the China/Vietnam coast after having triggered heavy rains all the way from the Philippine Sea.

A remnant circulation from Nock-Ten is forecast by global models to drift across Indi-China and set up some activity in the Bay of Bengal during the next week.

BIGGER STORM

Close on the heels of Nock-Ten, another bigger storm is forecast to brew over west Pacific and head west-northwest towards the eastern Chinese coast.

Enhanced activity over the west Pacific and the South China Sea from westward-to-north-westward propagating storms should normally have cascading impact on the Bay with a lag.

Meanwhile, a weather warning by the IMD and valid for the next two days said that heavy to very heavy rainfall would break out over Jammu and Kashmir, Himachal Pradesh, Uttarakhand, Uttar Pradesh, Bihar, sub-Himalayan West Bengal and Sikkim.

Isolated heavy rainfall has been forecast over Assam, Meghalaya, Arunachal Pradesh, Konkan, Goa, coastal Karnataka and Andaman and Nicobar Islands during this period.

WESTERLY TROUGH

The helpful weather features bringing this about is a persisting western disturbance over north Pakistan and neighbourhood with an offshoot upper air cyclonic circulation straddled across central Pakistan and adjoining northwest Rajasthan and Punjab.

The upper air cyclonic circulations over northwest Bay of Bengal and west Uttar Pradesh persists as does the feeble offshore trough from Gujarat coast to Karnataka coast.

A Kalpana-1 satellite imagery on Friday afternoon showed convective (rain-bearing) clouds rising over parts of plains of northwest, central and adjoining east and peninsular India, central and south Bay of Bengal, Andaman Sea and east Arabian Sea.

A short-term outlook valid until Monday said that widespread rain or thundershowers would be unleashed over the west coast and Andaman and Nicobar Islands.

RAINS FORECAST

Fairly widespread rain or thundershowers are also likely over northwest, central and adjoining peninsular India; Bihar, sub-Himalayan West Bengal, Sikkim, the North-eastern States and Lakshadweep.

But rainfall activity would decrease over parts of northwest India after two days.

Scattered rain or thundershowers would occur over remaining parts of the country except southeast peninsular India where it would be isolated.

An extended outlook valid until Wednesday said that fairly widespread rainfall would occur over many parts of the country except parts of northwest, east and southeast peninsular India where it would be scattered.

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