Bay of Bengal Low Pressure Triggers Heavy Rain Warnings

A newly formed low-pressure system over the North-West Bay of Bengal is set to bring widespread moderate to heavy rainfall across Bangladesh, meteorologists have warned. The system, centred near the coastal boundaries of West Bengal and North Odisha, features an expansive trough stretching across the southern delta of Bangladesh to the Indian state of Assam.

In its twenty-four-hour bulletin, the Bangladesh Meteorological Department noted that the South-West monsoon remains moderately active over the mainland and highly active over the North Bay of Bengal. This combination is expected to sustain persistent, heavy precipitation over the coming days, prompting warnings for both inland urban areas and maritime operations.

Deteriorating Weather Across Key Divisions

Under the influence of the low-pressure system, weather conditions are forecast to deteriorate rapidly. The meteorological office has predicted light to moderate rain, accompanied by temporary gusty winds and electrical storms, across most parts of the Rangpur, Mymensingh, Barishal, Chittagong, and Sylhet divisions. Meanwhile, residents in the Rajshahi, Dhaka, and Khulna divisions should prepare for sporadic, intense downpours.

Crucially, the weather office warned that isolated areas could experience exceptionally heavy falls. These localised downpours carry a high risk of waterlogging in urban centres, particularly in densely populated cities where drainage infrastructure is routinely overwhelmed by sudden volumes of water. Consequently, municipal authorities have been urged to clear drainage channels to mitigate localised flooding.

Out at sea, the active monsoon currents are generating volatile conditions. Maritime ports and fishing trawlers operating in the North Bay of Bengal have been advised to exercise extreme caution and remain close to the coastline due to rough seas and sudden squalls.

Recent Precipitation Records and Coastal Alerts

Recent rainfall records show that the wet weather is already taking hold. Sreemangal, situated in the tea-growing region of Moulvibazar, recorded the country’s highest rainfall of 51 millimetres in the twenty-four hours leading up to Wednesday evening. During the same period, the capital, Dhaka, received a lighter 7 millimetres of rain. However, meteorologists expect precipitation in the capital to intensify as the monsoon axis aligns.

With the low-pressure system expected to persist, disaster management teams in coastal districts have been put on high alert. The confluence of high-velocity winds, heavy rainfall, and active monsoon currents frequently triggers elevated tidal surges, threatening vulnerable riverside communities with sudden inundation. Local authorities are advising residents in low-lying coastal areas to monitor local weather broadcasts and prepare for potential evacuations if river levels rise beyond danger marks.