Heavy rain forecast, waterlogging feared in Dhaka, Chattogram cities

The Bangladesh Meteorological Department (BMD) has forecast "heavy to very heavy" rainfall across all eight divisions of the country as the southwest monsoon intensifies.

The downpours are likely to trigger temporary waterlogging in parts of Dhaka and Chattogram cities and pose a heightened risk of landslides in five southeastern hill districts: Chattogram, Rangamati, Bandarban, Khagrachhari, and Cox’s Bazar, according to a BMD alert issued on Saturday.

The Met Office said the heavy rain is expected to persist for 24 hours from 6pm, affecting large areas of Rangpur, Rajshahi, Khulna, Barishal, Dhaka, Mymensingh, Chattogram, and Sylhet divisions.

In the 24 hours to 6pm Saturday, Sylhet recorded the highest rainfall at 202 mm.

In addition, Chattogram saw 82mm, Mymensingh 76mm, Netrokona 62mm, and Srimangal 49 mm of rainfall.

As per BMD classifications, rainfall exceeding 88 mm in 24 hours is considered very heavy, while 44–88 mm is heavy, 23–43 mm moderately heavy, 11–22 mm moderate, and 1–10 mm light.

A persistent low-pressure system has been driving the recent spell of heavy rainfall across the country.

The Flood Forecasting and Warning Centre (FFWC) has warned of rising river levels due to both local rain and upstream runoff, with the potential for flooding in at least six districts.

Neighbouring India has also issued a red alert.

The India Meteorological Department (IMD) warned of rising water levels in the Teesta River, which originates in Chitamu Lake in the Sikkim Himalayas and flows into northern Bangladesh through Nilphamari’s Kaliganj border.

As a result, Bangladesh’s FFWC has flagged the risk of flooding in the Rangpur Division.

The Teesta, Dharla, and Dudhkumar rivers are expected to continue rising over the next three days, with the Teesta possibly breaching the danger level.

“River levels in Sylhet and Mymensingh divisions may cross the danger mark in the next two days due to upstream rainfall. Levels could begin to recede from the third day. In Chattogram Division, river levels are expected to start falling from Sunday,” said Sardar Uday Raihan, executive engineer at the FFWC, speaking to bdnews24.com.

According to the forecast, the Sari-Goyain, Jadukata, Dhalai, Someshwari, and Manu rivers in Sylhet and Mymensingh may rise sharply in the coming days, potentially flooding low-lying areas in Sylhet, Sunamganj, Netrakona, and Moulvibazar.

The Surma and Kushiyara rivers are also on the rise and are expected to continue increasing before starting to decline within 48 hours.

In the Rangpur Division, the Teesta, Dharla, and Dudhkumar rivers may flow close to or above warning levels over the next three days.

Meanwhile, the Gomti, Muhuri, Feni, Halda, Sangu, and Matamuhuri rivers in Chattogram are expected to remain steady for the next 24 hours before gradually falling over the following two days.

In the Ganges-Padma basin, river levels are expected to rise over the next five days but remain below danger levels.

Similarly, rivers in the Brahmaputra-Jamuna basin may rise during this period without crossing critical thresholds.