Overall rain deficit having been compressed to just six per cent as on Monday, an eventful year-2012 monsoon may just be preparing to sign off.
The India Meteorological Department (IMD) has picked up signals to the effect from the extreme northwest of the country.
LATE RALLY
Withdrawal of the season should have commenced from the first of September.
But a late rally by the monsoon extended its play through August and well into September.
The IMD said that an anti-cyclonic circulation (marked by sinking motion of air, high pressure and dryness) is developing over north-west India.
This is the exact reverse of a cyclonic circulation (ascending motion of air, lower pressure and humid conditions) that sustains the monsoon over land.
The building high-pressure and barren air would later give way to winter conditions, which expand coverage progressively from north-west India to the rest of the country.
The IMD said on Tuesday that the building meteorological conditions led it believe that the withdrawal might start from Monday (September 24).
VIGOROUS SESSION
Meanwhile, the monsoon was vigorous over Jammu and Kashmir, Himachal Pradesh, Uttarakhand, Punjab and east Uttar Pradesh during the 24 hours ending Tuesday morning.
Movement of western disturbances and formation of embedded cyclonic circulations are expected to sustain the rains for another week towards the east of the country.
An extended outlook valid for the next seven days said that rain or thundershowers would occur at many places over north-east India and Andaman and Nicobar.
But mainly dry weather would prevail over north-west, west and Central India.
GLOBAL OUTLOOK
Global models agreed with this outlook suggesting abrupt withdrawal of monsoon from entire northern half of the country (except east) during the last week of the month.
But rains are forecast to hold over south peninsula into the first week of October.
Meanwhile, a rain warning valid for Wednesday said that heavy to very heavy rainfall would occur over Jammu and Kashmir, Himachal Pradesh, Uttarakhand, Uttar Pradesh and Bihar.
Rains are expected to linger for another day over sub-Himalayan West Bengal, Sikkim, Assam, Meghalaya, Arunachal Pradesh and Andaman and Nicobar Islands.