South-West monsoon has withdrawn from some parts of Punjab, Haryana, Rajasthan and Gujarat on Monday in what looks like the precursor to an unusually rapid exit from the entire upper half of mainland India.
The hurried withdrawal is being attributed to its ‘release' from a temporary pause enforced around September 16 half way to the east by contra-indicating weather systems.
WEATHER INTERACTION
This was the phase when the build-up to withdrawal ran itself up against hyperactive interaction between a deep-seated trough in the western disturbance with easterlies from the Bay of Bengal triggering torrential rains over Uttarakhand, Haryana and Delhi.
After the interaction spent itself out, the way has become clear for the dry westerly-to-northwesterlies to push into these areas and expedite the withdrawal process all over again.
An India Meteorological Department (IMD) update on Monday said that the withdrawal line passed through Amritsar, Hissar, Jaipur, Udaipur, Ahmedabad and Porbandar.
MORE COVERAGE
Conditions are favourable for further withdrawal from remaining parts of Punjab, Haryana, Delhi, Chandigarh, Rajasthan, Gujarat, Jammu and Kashmir, Himachal Pradesh and Uttarakhand and even parts of Uttar Pradesh and Madhya Pradesh during the next two to three days.
Satellite picture also indicated drying up of moist air over parts of North-West India, the IMD update said.
But the weather being set up in peninsular India by active circulations in the Bay of Bengal and the Arabian Sea could keep the withdrawing monsoon at bay for the time being.
CONVECTIVE CLOUDS
Satellite pictures revealed the presence of convective clouds over parts of Arunachal Pradesh, Meghalaya, Tamil Nadu, North Orissa, South Chhattisgarh, South Konkan, Goa, South Peninsular India, East-Central and South Bay of Bengal, Andaman Sea and East-Central and South-East Arabian Sea. The IMD update said that during the last 24 hours ended Monday morning, widespread rainfall was reported from North Konkan, Goa and Coastal Karnataka.
It was fairly widespread over the Northeastern States, Madhya Maharashtra, Interior Karnataka, Kerala and Tamil Nadu while being scattered over Sub-Himalayan West Bengal, Sikkim, South Gangetic West Bengal and Lakshadweep.
The cyclonic circulation over Lakshadweep persisted from overnight.
SOUTH BAY WHIRL
International weather models suggested that occasionally wet weather would prevail over South Peninsular India until October 13, with another weather system forecast to take shape off South-East Tamil Nadu coast and just to the NorthEast of Sri Lanka.
The European Centre for Medium-Range Weather Forecasts (ECMWF) has predicted that a western disturbance could make its presence felt over the plains of North-West India by October 6.
This would be followed the very next day by the formation of a cyclonic circulation off South-East Tamil Nadu coast. It remains to be seen whether this could in fact mean the onset of the retreat monsoon (North-East or winter monsoon) over the peninsula.
In extended forecasts, the US National Centre for Environment Prediction (NCEP) sees this system driving rains across Tamil Nadu and Kerala as well as over parts of Karnataka and South Andhra Pradesh during the week ending October 13.
Meanwhile, an IMD weather outlook valid until Thursday said that fairly widespread rain or thundershowers would occur over Sub-Himalayan West Bengal, Sikkim, the North-Eastern States, Konkan, Goa, Tamil Nadu, Karnataka, Kerala, Lakshadweep and Andaman and Nicobar Islands.
They would be scattered over Interior Maharashtra, Andhra Pradesh, Orissa, Gangetic West Bengal and South Chhattisgarh.
But mainly dry weather would prevail over plains of North-West India, Bihar, Madhya Pradesh and Jharkhand indicating likely withdrawal of monsoon from these areas.
Extended forecast valid until Saturday said that fairly widespread rainfall would occur over South Peninsular India while rains would dry up over North-East India as well.
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