UNB, Dhaka :Maritime ports of Chittagong, Cox’s Bazar, Mongla and Payra have been asked to hoist local cautionary signal no three as deep convection is taking place over North Bay.Under its influence, squally weather may affect North Bay, adjoining coastal area of Bangladesh and the maritime ports, said a release of Met office.All fishing boats and trawlers over the North Bay have been advised to come close to the coast and proceed with caution until further notice.