Monsoon is likely to have withdrawn from no more than the western one-third of the country by the month-end.

This is according to projections made available by the US National Centres for Environmental Prediction.

RAINS TO LINGER

This could be taken to mean that the rains would linger over parts of east and west coasts and almost the entire central and peninsular India through the month-end.

This would in turn set the monsoon withdrawal process back by a long shot.

There is belated monsoon activity to be had for the entire east coast right until September 30.

Enhanced sea-surface temperatures in the western equatorial Indian Ocean are forecast to fuel convection (cloud building) and guide flows across the peninsula into the Bay of Bengal and even beyond.

PACIFIC STORM

These flows are actually being directed into a raging Tropical Storm Roke in the northwest Pacific, which is forecast to track west towards Taiwan or southeast China coast. Westward moving storms in the northwest Pacific or adjoining South China Sea are known to send in a ‘pulse' into the Bay of Bengal.

On Thursday, the low pressure system over northwest Bay of Bengal has washed up ashore over Gangetic West Bengal, an update by India Meteorological Department (IMD) said.

WASHES OVER

The western disturbance persisted over north Pakistan and adjoining Jammu and Kashmir while the offshore trough ran down from Gujarat coast to Kerala coast.

A weather warning said that isolated heavy to very heavy rainfall would occur over Punjab, Haryana, Delhi, Chandigarh, Himachal Pradesh and Uttarakhand on Friday and isolated heavy rain on Saturday.

Isolated heavy rainfall would also break out over Gangetic West Bengal, Orissa, Chhattisgarh, coastal Karnataka, Kerala, Arunachal Pradesh, Assam, Meghalaya and Nagaland, Manipur, Mizoram and Tripura on Friday and Saturday.