The deep depression over Southeast Bay and adjoining Southwest Bay intensified into cyclonic storm AMPHAN at 9pm on Saturday, the Met Office said in a weather bulletin.
“It is likely to intensify further and move in a north-westerly direction,” the forecast said.
It said a trough of westerly low lies over West Bengal and adjoining area.
Bangladesh Meteorological Department (BMD) has forecast rain or thundershower accompanied by temporary gusty or squally wind for parts of Rangpur, Mymensingh and Sylhet divisions.
It said the weather may remain mainly dry with temporary partly cloudy sky elsewhere over the country.
Inclement weather at a time when paddy harvesting is going on will be an unwelcome development for farmers. Rain and storm at this time could jeopardise the harvest.
Meanwhile, a mild heat wave is sweeping over Khulna division and the regions of Madaripur, Gopalgonj, Rangamati, Rajshahi, Pabna and Patuakhali may continue, the Met Office said.
Temperature during the day and night may remain nearly unchanged.
In the last 24 hours until 6pm, Netrokona recorded the highest rainfall of 44mm. During this period, the highest temperature was recorded at 37.8 degrees Celsius in Jashore. Netrokona recorded the lowest temperature at 21.4C.
In its extended outlook for the next five days, the Met Office said rain or thundershowers activity may increase.
Also read: Rain, thundershowers likely