The final days of the Bengali month of Ashar are drawing to a close. Shraban begins in just one day. The monsoon winds have now become active across the country, bringing widespread heavy to very heavy rainfall. Although Dhaka did not experience particularly heavy rain yesterday, rainy conditions continue to prevail, and many streets and alleys remain waterlogged.
From 6:00 a.m. on Sunday to 9:00 a.m. on Monday (a period of 27 hours), 110 mm of rainfall was recorded in the capital. On Monday alone, 97 mm of rain fell in Dhaka. Heavy rainfall has continued unabated in many districts. The highest rainfall in the country was recorded in the Ambagan area of Chattogram, with 174 mm.
According to the latest special bulletin from the Bangladesh Meteorological Department (BMD), rainfall is expected to ease somewhat over the next two days but may intensify again on July 16 and 17.
From 6:00 a.m. today through the next 48 hours, rainfall is expected to decrease slightly across all divisions of the country. During this period, 76–100% of the country may experience temporary gusty or squally winds accompanied by light to moderate rain or thundershowers. Daytime temperatures are expected to range between 31°C and 36°C, while nighttime temperatures may remain between 24°C and 28°C.
Beginning July 16, rainfall is expected to increase again over the following 48 hours. Most parts of the country could experience moderately heavy to very heavy rain, accompanied by thunderstorms.
Rivers Above Danger Levels
The Flood Forecasting and Warning Centre (FFWC) of the Bangladesh Water Development Board reported that, as of 9:00 a.m. Monday, water levels at four monitoring stations on the Surma, Kushiyara, and Someshwari rivers were flowing above the danger level.
- At Chatak on the Surma River in Sunamganj, the water level was 15 cm above the danger mark.
- At Fenchuganj on the Kushiyara River in Sylhet, it was 27 cm above the danger level.
- At Markuli in Sunamganj, the Kushiyara River was also slightly above the danger mark.
- At Kolmakanda in Netrokona, the Someshwari River was 8 cm above the danger level.
Meanwhile, river levels at Kanaighat, Sylhet Sadar, Sunamganj (Surma River), Dalia and Kaunia (Teesta River), and Haripur (Muhuri River) are approaching danger levels.
Meteorologist Muhammad Abul Kalam Mallik said the monsoon has become even more active over Bangladesh, prompting authorities to issue another warning for heavy to very heavy rainfall. While rainfall may decrease slightly from Tuesday, it could increase again from Thursday as the monsoon strengthens once more.
Why the Rain Is So Intense
Mostafa Kamal Palash, a weather and climate researcher at the University of Saskatchewan, Canada, explained that a low-pressure system over the northwestern Bay of Bengal has been moving slowly, allowing huge amounts of moisture to flow into Bangladesh from the Bay for more than a week.
As this moisture-laden air is blocked by the hills of Chattogram, the Chittagong Hill Tracts, Tripura (India), and the Rakhine Mountains (Myanmar), an orographic effect has caused prolonged heavy to very heavy rainfall in these regions.
Meteorologists also noted that the continuous rainfall has been driven by several combined factors: The low-pressure system over the northern Bay of Bengal, unusually active monsoon conditions, changes in prevailing wind patterns, and the influence of
Flood Risk in Nine Districts
According to the FFWC's regular flood forecast, low-lying riverbank areas in at least nine northern and northeastern districts may experience new short-term flooding or worsening flood conditions within the next 24 to 48 hours.
The districts at risk include: Sylhet, Sunamganj, Netrokona, Sherpur, Mymensingh, Nilphamari, Lalmonirhat, Rangpur, Kurigram.
However, the agency expects conditions in the hill districts to improve somewhat. Flooding along the Sangu and Matamuhuri rivers in Bandarban, Chattogram, and Cox's Bazar is expected to continue receding over the next 24 hours.
