Heavy rain may shift eastwards from North-West

The rain-spewing low-pressure area over Haryana started to ‘blink’ on Sunday in an apparent give-and-take gesture after a counterpart system sprang up over Bengal and started moving towards Central India.

Two active ‘lows’ cannot normally coexist over land in a single monsoon system, though exceptions are possible depending on the sheer strength of the moisture feed from the seas to both sides of the peninsula.

An India Met Department (IMD) update said that the pre-existing ‘low’ traced to over North Haryana and adjoining Punjab by Sunday evening would weaken by Monday morning.

Rainfall to reduce

This would progressively scale down the intensity of its productive interaction with a persisting western disturbance – itself a low-pressure band of air periodically travelling to the East – lessening the rainfall activity over the region. Ongoing widespread rainfall with isolated heavy to very heavy falls over Jammu & Kashmir, Himachal Pradesh, Uttarakhand, Punjab and Haryana, Chandigarh and Delhi may continue on Monday and reduce thereafter.

The counterpart ‘low’ over the Bengal and adjoining Jharkhand may trigger fairly widespread to widespread rainfall with isolated heavy to very heavy falls over the plains of Bengal, Odisha, Jharkhand and Bihar during next two days.

As per the wind-field projections of the IMD, this ‘low’ is too may push into the East, Central and adjoining North-West India and could likely be readying itself for the longer haul.

The system is projected to be active in the region right until August 27 till when forecasts are available, thanks also to incremental flows from a circulation, till now moving a friendly direction in the North-West Pacific.

But contrary to earlier forecasts, the US Joint Typhoon Warning Centre says that the system may likely be yanked away to the East-North-East by the western disturbance system, and become unimportant from the monsoon perspective.

As if on cue, the IMD has withdrawn its forecast for heavy rainfall forecast for Kerala and Coastal Karnataka from Tuesday (August 20) as also the outlook for strong winds over the South-West Arabian Sea.

But a three-day, five-day and 10-day outlook from the European Centre for Medium-Range Weather Forecasts sees progressively increasing rainfall cover over Kerala and Karnataka coasts, Central India and along foothills of the Himalayas.

The Climate Prediction Centre of the US National Weather Services sees scope for at least two more circulations/‘low’s materialising over the Odisha and Andhra Pradesh coasts over the next 15 days.

Rainfall scenario for the country as a whole indicated a comfortable position (surplus of two per cent as on date) with individual deficits in the affected seven Met subdivisions having been contained at 30 per cent or less.