The rain-maker Madden-Julian Oscillation (MJO) wave is in the process of exiting the East Indian Ocean after depositing a low-pressure area in the Bay of Bengal and reviving the monsoon, but the area of enhanced precipitation will move out along with the wave to South-East Asia.
The MJO wave is expected to be of some consequence to India as it enters re-energised into the South China Sea and adjoining West Pacific, and in a 'reverse kick' lets loose a rain wave back to the Bay of Bengal from the remnant of a tropical storm likely developing around the Philippines.
The US Climate Prediction Centre sees this rain wave in the Bay hitting the East Coast of India along the Andhra Pradesh coast and triggering another spell over Andhra Pradesh, Telangana, Vidarbha, Central Maharashtra and South Madhya Pradesh during next (last) week of August.
Low-pressure area weakens
On Wednesday, the previous day's low-pressure area that emerged over land from the Bay of Bengal has weakened into a cyclonic circulation. India Meteorological Department (IMD) spotted it over Jharkhand and expects it to move across North-East Madhya Pradesh during the next two days.
The day also saw heavy to heavy rainfall over the plains of West Bengal, Sikkim, Marathawada, Arunachal Pradesh and Chhattisgarh and heavy over Madhya Pradesh, Vidarbha, Gujarat, Assam, Meghalaya, Tripura, Madhya Maharashtra, Tamil Nadu, Puducherry, Karaikal, Telangana and Odisha.
The western end of the monsoon trough lies north of its normal position but may shift back to its normal position in the next two days to receive the incoming circulation. This will revive the monsoon yet again over North-West India. The eastern end is already in the normal position.
Rains to return to North-West
Scattered to fairly widespread rainfall with isolated heavy falls is forecast over East Uttar Pradesh and Uttarakhand from Thursday to Saturday; over Himachal Pradesh, Haryana and West Uttar Pradesh on Friday and Saturday; isolated heavy to very heavy over Uttarakhand on Thursday and Friday. Fairly widespread rain with isolated heavy falls is likely over Bihar from Friday to Sunday.
With the weakening of the low-pressure area, the remnant circulation has opened out a North-South trough from Vidarbha to Coastal Tamil Nadu across Telangana and Rayalaseema. This is a corridor of potential weather activity along the East Coast, which models indicated from early on.
More rain for Gujarat, Odisha
The IMD has forecast enhanced rainfall activity over Central and adjoining North Peninsular India during next 2-3 days. Fairly widespread to widespread rain with isolated heavy falls is likely over Gujarat, Maharashtra, Odisha, Jharkhand and plains of West Bengal on Wednesday and Thursday; over Madhya Pradesh until Friday; and over Telangana and Chhattisgarh on Wednesday.
Widespread rainfall activity with isolated heavy to very heavy falls will continue over North-East India and the plains of West Bengal and Sikkim for two more days. The rain activity may relent during the subsequent three days, with isolated heavy rainfall marking the overall weather.