Dhaka: Bangladesh Meteorological Department (BMD) has forecast that several severe thunderstorms accompanied by hail and multiple spells of heatwaves are likely across the country during the current month.
According to Bangladesh Sangbad Sangstha, the Met office’s long-range forecast issued on May 3 suggests that the country may experience 5-8 days of light to moderate thunderstorms, including 2-3 days of severe thunderstorms with hail at different places.
Rainfall is expected to remain normal nationwide. Meanwhile, one to two low-pressure systems may develop over the Bay of Bengal, with one potentially intensifying into a depression or cyclone. The forecast also indicates that one to three mild (36-37.9°C) to moderate (38-39.9°C) heatwaves and one severe heatwave (40-41.9°C) could sweep across the country during the month. However, overall day and night temperatures are likely to remain near normal.
Major rivers are expected to flow within normal levels, although isolated heavy rainfall may temporarily raise water levels in northern, northeastern, and southeastern regions. The average daily evaporation is projected to range between 3.5 and 5.5 mm, while average sunshine duration may be 5.5 to 7.5 hours per day.
The forecast was finalized at a meeting of the Expert Team on Long-Range Weather Forecasting held on May 3 at the Storm Warning Centre in Dhaka, where April’s weather data were reviewed. Analysis shows that Bangladesh recorded above-normal rainfall (+75.7%) in April, with all divisions experiencing normal rainfall overall. Moderately heavy to very heavy rainfall occurred widely during April 6-9 and 26-30.
Additionally, light to moderate rainfall accompanied by lightning, hail, gusty winds, and squalls was observed on most days due to interactions between westerly and easterly wind flows. The highest daily rainfall in April was recorded at Nikli in Kishoreganj, measuring 160 mm on April 28.
Mild to moderate heatwaves affected various parts of the country during April 1-4, 12-15, 17-19, and 20-26, influenced by a thermal low over West Bengal and adjoining areas of Bangladesh. The highest temperature recorded during the month was 40.0°C in Rajshahi on April 22, while the lowest temperature was 16.0°C in Rangamati on April 10.
Overall, maximum and mean temperatures were slightly below normal by 0.6°C and 0.1°C respectively, while minimum temperature was 0.4°C above normal. The observed weather patterns in April-including temperature trends, heatwaves, thunderstorms, Kalbaishakhi activity, and river conditions-were largely consistent with the monthly forecast.