The monsoon low over northwest bay off West Bengal-Bangladesh coast intensified into a well-marked low over the same area, reports UNB.
It is likely to intensify further and move in a northwesterly direction. Its associated steep pressure gradient persists over the north bay.
Squally weather may affect the ports and sea will remain moderate, said a Met Office bulletin.
Maritime ports of Chittagong, Cox's Bazar and Mongla have been advised to keep hoisted local cautionary signal number three.
All fishing boats and trawlers over north bay and deep sea have been advised to remain close to the coast and proceed with caution until further notice.