The US Joint Typhoon Warning Centre has located the low-pressure area over East-Central Bay of Bengal to 714 km South of Chittagong in Bangladesh this morning.
This is expected to intensify into a depression by tomorrow or the day after, it said. The India Met Department (IMD) is of the view that the intensification may happen by tomorrow itself.
LANDFALL TOMORROW?
It maintained the outlook for the depression-in-the-making to move in a west-north-west direction towards the North Andhra Pradesh and South Odisha coast.
It is likely to cross the South Odisha-North Andhra Pradesh coasts by tomorrow and move further west-north-west across Chhattisgarh and Madhya Pradesh subsequently.
The European Centre for Medium-Range Weather Forecasts has located two circulations in the Bay, which would converge to set up the depression and cross the Andhra Pradesh coast.
Fairly widespread to widespread rainfall with thunderstorms and lightning are forecast for Bengal and Odisha for three days from today, the IMD said.
A similar forecast is valid, and is already happening, over coastal Andhra Pradesh and would last for three days over Chhattisgarh and Telangana tomorrow and the day after; over Madhya Pradesh on Friday and Saturday; and parts of North-West India on Saturday and Sunday.
A detailed forecast said heavy to very heavy rain, with extremely heavy falls over Odisha and north coastal Andhra Pradesh, is expected tomorrow (Thursday).
RAIN FORECAST
It will be heavy to very heavy over Telangana and heavy over Nagaland, Manipur, Mizoram, Tripura, the plains of Bengal, Jharkhand and Chhattisgarh.
Friday: Heavy to very heavy rain with extremely heavy falls over Odisha; heavy to very heavy rain over Chhattisgarh; and heavy over Assam, Meghalaya, Vidarbha, Madhya Maharashtra, the plains of Bengal, East Madhya Pradesh, South Konkan, Goa, Jharkhand and Telangana.
Saturday: Heavy rain over West Uttar Pradesh, Uttarakhand, Haryana, Chandigarh, Delhi, East Rajasthan, Madhya Pradesh, South Konkan, Goa and coastal Karnataka.
Meanwhile, the IMD did not refer to the further scope for strengthening of the depression, apparently because the sea-surface has not warmed much beyond the threshold 27-29 deg Celsius.
Vertical wind shear values, which refer to a sudden change in wind direction with height that unsettles a building system, are low to moderate at 37 km/hr.
They tend to be high during the active phase of the monsoon, which is why tropical cyclones are rare during the monsoon. But cyclones tend to develop during the monsoon transition phase.