The season’s fiercest Nor’wester lashed the city on Sunday evening, felling trees and disrupting traffic.

According to police, 27 trees were uprooted in various parts of the city in the storm. Vehicles slowed down or had to be diverted on at least 16 roads.

Ganesh Chandra Avenue, Belgachhia Road, Sundari Mohan Avenue, VIP Road, Bidhan Sarani (near Thanthania), Raja Subodh Mullick Road (near Jadavpur University) and Kalighat Road were the worst affected.

Two eucalyptus trees fell across the boundary wall of Salt Lake’s BD Park on an adjoining three-storey house.

Residents alleged that the recent digging of a trench along the boundary to shift the BD Block market to the park had weakened the trees’ base.

Flights could not take off from or land at Netaji Subhas Chandra Bose International Airport from 6.45pm to 7.30pm.

The Air India Agartala-Calcutta flight was diverted to Bhubaneswar after it failed to land at Dum Dum. It returned to the city at night.

The Dhaka-Calcutta flight of GMG airline returned to the Bangladesh capital for the same reason.

Seven flights had to hover over Calcutta for half an hour on an average before landing, said airport officials. Take-off of two Jet Airways and two Kingfisher flights to Mumbai and Delhi were delayed by more than 30 minutes by the storm.

Train services, too, were hit by the storm. Eastern Railway’s Sealdah South section was the worst affected after a tree fell on overhead electrical wires near Sealdah around 7pm.

The tree was removed but technicians could not fix the snapped wires till late on Sunday. Trains could not enter or leave Sealdah station, leaving thousands of passengers stranded.

The Madhyamgram section witnessed disruptions for half an hour from 7pm, after a tree fell on the tracks.

There were delays along the Howrah-Bandel Main line because of frequent power interruptions between 7pm and 7.30pm.

A railway official said an advertisement banner got entangled in overhead wires, causing the power disruptions.