Bay Depression Triggers Signal No. 3 at Seaports

A well-marked low-pressure area has developed over the north-west Bay of Bengal and the adjoining coastal regions of northern Odisha and West Bengal, prompting the Bangladesh Meteorological Department (BMD) to issue Local Cautionary Signal No. 3 for the country’s four seaports amid forecasts of squally weather along the coast.

The BMD said the weather system is expected to intensify rainfall activity across large parts of the country over the coming days, bringing gusty winds to coastal areas and the Bay of Bengal. As a precaution, the ports of Chattogram, Cox’s Bazar, Mongla and Payra have been instructed to hoist Local Cautionary Signal No. 3 to alert vessels and port authorities to potentially hazardous maritime conditions.

The warning was confirmed on Saturday by BMD meteorologist Dr Abul Kalam Mallik, who said the influence of the well-marked low would result in widespread spells of rain and thunderstorms accompanied by gusty winds throughout the week.

He said intermittent rainfall is likely across much of Bangladesh, although the Chattogram and Sylhet divisions are expected to receive comparatively heavier precipitation because of the system’s location and prevailing monsoon conditions.

Meteorologist Abdul Hamid echoed the forecast, saying the low-pressure system is likely to produce moderate to moderately heavy rainfall in many parts of the country during the week. Heavy rainfall remains likely in the Chattogram and Sylhet regions, raising the possibility of temporary waterlogging in low-lying areas if prolonged showers occur.

To ensure safe navigation, the BMD has also instructed all inland river ports to display Cautionary Signal No. 1. Such warnings are routinely issued during the monsoon season when low-pressure systems over the Bay of Bengal create conditions favourable for strong winds, thunderstorms and rough rivers.

Meteorologists said the system is being monitored continuously, as well-marked low-pressure areas can sometimes strengthen further under favourable atmospheric and oceanic conditions. Although no cyclone warning has been issued, fishing boats, trawlers and other small vessels operating near the coast have been advised to remain cautious and closely follow official weather updates.

The developing weather system is also expected to bring relief from the mild heatwave currently affecting several districts. According to the latest BMD observations, Rajshahi, Pabna, Nilphamari, Panchagarh, Kurigram, Feni and Chuadanga are experiencing mild heatwave conditions.

Dr Mallik said increasing cloud cover and widespread rainfall are likely to weaken the heatwave from Sunday onwards. As rain becomes more widespread, temperatures are expected to ease across most parts of the country.

The latest forecast indicates that daytime temperatures may fall slightly nationwide, with a more noticeable decline expected by Monday. Maximum temperatures could decrease by between one and three degrees Celsius as the influence of the low-pressure system strengthens.

Low-pressure systems frequently develop over the Bay of Bengal during the southwest monsoon, drawing moisture inland and producing widespread rainfall. While these systems are essential for replenishing water resources and supporting agriculture, they can also disrupt shipping, affect fishing operations and increase the risk of flash floods and waterlogging in vulnerable areas.

Authorities have urged residents, particularly those living in coastal districts and flood-prone regions, to remain vigilant and follow official weather advisories. Mariners, fishermen and operators of inland vessels have also been advised to exercise caution until conditions improve.

With widespread rain, gusty winds and rough seas expected over the coming days, the Bangladesh Meteorological Department will continue to monitor the movement and intensity of the low-pressure area and issue further advisories as necessary.