Heavy rain, thunderstorms and heatwave: Wednesday to see weather whiplash

A fresh weather system is gathering strength over the Bay of Bengal, setting the stage for another active monsoon spell across large parts of India. Here's what the latest forecast says.

In Short

• Heavy rain expected in Bihar and several northeastern states
• Thunderstorms with gusty winds likely in multiple regions
• Heatwave persists in parts of southern India

The India Meteorological Department (IMD) has forecast a day of intense weather across large parts of the country on Wednesday, July 15, with extremely heavy rainfall likely over Odisha, heavy rain in Bihar and several northeastern states, thunderstorms accompanied by gusty winds in multiple regions.

It's not only rain though, as heatwave conditions are also expected to persist over parts of southern India.

The forecast comes as the southwest monsoon remains active, with weather systems over the Bay of Bengal expected to sustain widespread rainfall over eastern and adjoining parts of the country.

HEAVY RAIN TO ARRIVE

According to the IMD, Odisha is likely to receive heavy to very heavy rainfall, with isolated places expected to witness extremely heavy rainfall, while Bihar is forecast to receive heavy to very heavy rain on July 15.

Heavy rainfall is also likely in isolated places throughout Arunachal Pradesh, Assam and Meghalaya, Chhattisgarh, Jharkhand, Nagaland, Manipur, Mizoram and Tripura, Uttarakhand, and Sub-Himalayan West Bengal and Sikkim.

The weather office has also forecast thunderstorms accompanied by lightning and gusty winds of 40-50 kmph over Gangetic West Bengal, Jammu and Kashmir, Jharkhand, and the Andaman and Nicobar Islands.

Winds of 30-40 kmph are expected over parts of Andhra Pradesh, Bihar, Karnataka, Kerala, and Telangana, while strong surface winds are likely over Andhra Pradesh, Karnataka, Kerala and Telangana.

Meanwhile, heatwave conditions are likely to continue in isolated pockets of coastal parts of Andhra Pradesh and Tamil Nadu, Puducherry and Karaikal.

Hot and humid weather is also expected over Haryana, Delhi, Punjab, Uttar Pradesh, parts of Karnataka, Telangana, and Tamil Nadu.

MONSOON TO REMAIN ACTIVE

The widespread rainfall is being driven by an active southwest monsoon and favourable atmospheric conditions.

The IMD said the monsoon trough currently extends from Jammu across north India to the north Bay of Bengal, while an upper-air cyclonic circulation persists over the north Bay of Bengal and adjoining south Bangladesh.

Under its influence, a low-pressure area is likely to form over the north Bay of Bengal and adjoining West Bengal-Bangladesh coasts during the next 24 hours, which is expected to strengthen monsoon activity over eastern India.

The southwest monsoon normally covers the entire country by early July and is responsible for nearly 70% of India's annual rainfall, making it vital for agriculture, reservoirs, hydropower generation and drinking water supplies.

Low-pressure systems that develop over the Bay of Bengal are among the primary drivers of active monsoon spells, often bringing widespread rain to eastern, central and northern India.

- Ends