Cyclone likely in Bay later this month, severe Nor'westers feared

One or two low-pressure systems may form in the Bay of Bengal in the second half of May and one of them could intensify into a depression or cyclone, according to the Bangladesh Meteorological Department (BMD).

Md Bazlur Rashid, a meteorologist at the BMD's Storm Warning Centre, told BSS that the country may also experience Nor'westers, thunderstorms and one to three heatwaves during the month.

He said scattered light to moderate Nor'westers and thunderstorms may occur for five to eight days in May, while severe Nor'westers may hit the country for two to three days. Hailstorms may also occur in some areas, he added.

The forecast further said one to three mild to moderate heatwaves may sweep over different parts of the country this month and one of them could turn severe, pushing temperatures to 40-41.9 degrees Celsius.

Md Momenul Islam, BMD director (current charge) and chairman of the Expert Committee on Long-Range Forecast, said the country is likely to receive normal rainfall in May, although heavy rainfall may occur in some regions.

According to the divisional forecast, Sylhet division may receive the highest rainfall, ranging between 520 and 540 millimetres.

Mymensingh division may see 340-360 millimetres, Chattogram 330-350 millimetres, Rangpur 260-280 millimetres and Dhaka division 250-270 millimetres.

Barishal division is likely to receive 220-250 millimetres of rainfall, while Rajshahi may get 170-190 millimetres and Khulna 160-180 millimetres.

The forecast said river flow in the country's major rivers is expected to remain normal in May. However, isolated heavy rainfall in the northern, northeastern and southeastern regions may temporarily increase water levels.

According to the agricultural weather outlook, the average daily evaporation rate may remain between 3.5 and 5.5 millimetres, while the average duration of sunlight may range from 5.5 to 7.5 hours.

Meteorologists said the rainfall and soil moisture conditions will be favourable for seasonal agricultural activities.

BMD data showed that the country recorded 75.7% higher rainfall than normal in April this year. Most divisions experienced above-normal rainfall, while rainfall in Rajshahi division remained close to normal.

Barishal division recorded the highest rainfall deviation with 169.5% more rainfall than normal. Mymensingh division recorded 150.9% higher rainfall, while Sylhet division received 104.4% more rainfall than average.

In Dhaka division, rainfall reached 213 millimetres against the normal level of 119 millimetres. Sylhet division recorded 603 millimetres of rainfall compared to the normal 295 millimetres.

Meteorologists said heavy to very heavy rainfall occurred across most parts of the country in April due to the combined influence of western low pressure and easterly winds.

Significant rainfall, thunderstorms and gusty winds were recorded from 6 to 9 April and again from 26 to 30 April. Hailstorms also affected several areas during the period.

The country's highest single-day rainfall in April was recorded in Nikli of Kishoreganj district, where 160 millimetres of rainfall was measured on 28 April.

Several spells of heatwaves also swept across the country during April due to a thermal low-pressure system over West Bengal and adjoining western parts of Bangladesh.

The highest temperature of the month was recorded at 40 degrees Celsius in Rajshahi on 22 April, while the lowest temperature was 16 degrees Celsius in Rangamati.