The cyclonic circulation from South China Sea has landed in the North-East Bay of Bengal which is forecast to develop as a low-pressure area over adjoining North Bay of Bengal on Wednesday, promising to escalate an indifferent monsoon to a cogent, organised and productive weather system.
Even ahead of the low, the south-westerly/westerly winds have strengthened over the Arabian Sea and over the southern parts of Bay of Bengal and Andaman Sea, the India Meteorological Department (IMD) said. This is what will catapult the monsoon into an active phase over Central and Peninsular India.
Active phase
This active phase would last at least for three-to-four days from Tuesday, bringing the West Coast and West India under its spell. Widespread rainfall with scattered heavy to very heavy rainfall with isolated extremely heavy falls has been forecast over Konkan and Goa until Wednesday.
As for adjoining Mumbai, heavy to very heavy rainfall on Monday will be followed by isolated extremely heavy falls on Tuesday and Wednesday. A similar outlook is valid for Madhya Maharashtra including the Ghat areas. Heavy to very heavy falls also very likely at a few places over Coastal Karnataka and at isolated places over Kerala and Marathawada for four days until Friday.
The crucial monsoon trough over North India has shifted as a whole to its normal position and lay extended on Monday evening from Ganganagar in West Rajasthan linking Hissar, Badaun, Gonda, Azamgarh, Gaya, Jamshedpur and Digha before dipping south-eastwards into the North-East Bay of Bengal.
This is the most ideal for the monsoon trough to be in; formation of a low-pressure area in the Bay is a pre-condition for the eastern end of the trough to behave. Active monsoon conditions are generated when it finds it moorings in the Bay, anchored in the waters along with the low-pressure area.
Successor in the making?
This apart, the monsoon would also have the assured comfort from an East-West wind convergence zone along the Kolhapur-Hyderabad-Visakhapatnam alignment where the low-pressure area would be ensconced. It would travel over Madhya Pradesh and Gujarat before sliding into the North Arabian Sea.
Short to medium-range model guidance from the India Meteorological Department (IMD) suggests the formation of a successor low-pressure area in the Bay any time after August 8, and the seas there continuing to be in an animated state into the middle of August, sustaining active monsoon conditions.
Rains to stay until Aug 10
Widespread rainfall with heavy to very heavy rainfall and extremely heavy falls is likely over Gujarat State on Wednesday and Thursday. Widespread rainfall with heavy to very heavy rainfall is also forecast over Odisha, Gangetic West Bengal, Jharkhand and Chhattisgarh until Wednesday.
An extended outlook for three days from August 8-10 predicted widespread rainfall/thundershowers with scattered heavy to very heavy falls and isolated extremely heavy falls over Kerala and the Ghat areas of Tamil Nadu and South Interior Karnataka and also over Uttarakhand and adjoining North-West Uttar Pradesh.
Widespread rainfall/thundershowers with scattered heavy to very heavy falls are also likely over the North-Eastern States and parts of Punjab and Haryana. Scattered to fairly widespread rainfall with isolated heavy falls are likely over the rest of India outside West Rajasthan, Gujarat, Interior Maharashtra and Andhra Pradesh where isolated to scattered rainfall is likely during this period.