A depression over the Bay of Bengal is expected to trigger widespread rainfall across the country over the next five days, with some areas likely to receive moderate to very heavy downpours, according to the Bangladesh Meteorological Department (BMD).
The depression was located over the west--entral and adjoining northwestern Bay of Bengal at 6am on Tuesday and may intensify into a deep depression within the next 12 hours, the BMD said in its 120-hour forecast issued at 9AM on Tuesday.
The system developed from a well-marked low-pressure area over the east-central and adjoining west-central Bay of Bengal before moving west-northwestward and intensifying.
The monsoon axis currently extends from Uttar Pradesh and Bihar through West Bengal and central Bangladesh to Assam. The southwest monsoon remains fairly active over Bangladesh and strong over the northern Bay of Bengal.
On Tuesday, light to moderate rain or thundershowers accompanied by temporary gusty winds are likely at a few places in Dhaka, Khulna, Barishal and Rajshahi divisions, and at one or two places in Rangpur, Mymensingh, Chattogram and Sylhet divisions.
Some areas may also experience moderate heavy rainfall.
The mild heatwave affecting parts of Dhaka, Tangail, Faridpur, Gopalganj, Kishoreganj, Narayanganj, Rajshahi, Pabna, Sirajganj, Khulna, Jashore and Chuadanga districts, as well as parts of Mymensingh and Sylhet divisions, may ease in some areas.
Day and night temperatures are also likely to fall slightly across the country.
Rainfall is expected to increase from Wednesday (September 23), when many areas of Rangpur, Rajshahi, Khulna, Barishal and Chattogram divisions and some areas of Mymensingh, Dhaka and Sylhet divisions may experience rain or thundershowers with gusty winds.
Moderate to very heavy rainfall could occur at isolated places.
Similar weather conditions are expected to persist on Thursday (September 24), with rain likely at many places in Rangpur, Rajshahi, Khulna, Barishal and Chattogram divisions and at some places in Dhaka, Mymensingh and Sylhet divisions.
On Friday (September 25), many areas of Rajshahi, Khulna and Barishal divisions, along with some areas of other divisions, may receive rainfall. Moderate to heavy rain is likely at some places in Rajshahi, Khulna and Barishal divisions.
On Saturday (September 26), temporary gusty winds accompanied by light to moderate rain or thundershowers may affect some areas of Rajshahi, Rangpur, Dhaka, Mymensingh, Khulna, Barishal, Chattogram and Sylhet divisions. Some areas may receive moderate heavy rainfall.
The BMD said the country's overall rainfall or thundershower activity may gradually decrease after the five-day period.