Low Pressure Likely in Bay of Bengal This August, Flash Floods Possible

Bangladesh is expected to experience overall normal rainfall in August, but face risks of thunderstorms, low-pressure systems, and short-term flooding, according to the Bangladesh Meteorological Department (BMD).

Both day and night temperatures are also likely to remain slightly above normal throughout the month. The forecast was detailed in a official notification signed by Md. Azizur Rahman, Director (Current Charge) and Chairman of the Expert Committee of the BMD.

According to the meteorology department, one to two seasonal low-pressure systems may form in the Bay of Bengal this month, with at least one potentially intensifying into a seasonal depression. Across the country, light to moderate thunderstorms are expected on 5 to 6 days.

Additionally, one or two mild-to-moderate heatwaves could sweep over parts of the country during this period. The average daily evaporation is projected to range between 2.5 and 4.5 mm, while average daily sunshine hours are expected to be between 5.5 and 6.5 hours.

Regarding rainfall and river conditions, the forecast warns that heavy downpours could trigger short-term flash flood situations in the northern, northeastern, and southeastern hilly regions of the country. Overall, water levels in Bangladesh’s major rivers are expected to rise.

A review of July's weather showed that the country received 35.6% more rainfall than normal overall. Chattogram division recorded the highest excess rainfall at 59%, followed by Sylhet with 37.3% more rain than usual. On the other hand, Mymensingh division received 0.05% less rainfall than normal.

Three low-pressure systems formed in the Bay of Bengal in July, two of which developed into seasonal depressions. The highest temperature in the country last month was recorded in Rajshahi at 37.5°C on July 4, while the lowest was in Sylhet at 22°C on July 21 and 22. Chattogram recorded the highest daily rainfall of the month on July 8, at 329 mm.