Air and train traffic was affected in Kolkata due to norwester winds that lashed the city and its adjoining districts last evening. None of the scheduled 10 flights were able to take off or land at the Netaji Subhas Chandra Bose International Airport between 7.30 pm and 8 pm due to the storm. Airport sources said, air traffic started normalising after 8 pm. Trees uprooted due to the norwester halted train services for about one and a half hours in both Metro Railway and the Eastern Railway's Sealdah South section.