NEW YORK, Nov. 15 (Xinhua) -- The first snow of this winter season hit New York City on Thursday afternoon, causing traffic disruption, flight cancellations and travel difficulties.

The snow, which started early in the afternoon, was sweeping across the city's five borough, with a maximum accumulation of up to 5 inches (12.7 cm) in the Bronx, the northernmost borough.

Flight activity at Kennedy Airport ?was disrupted by the extreme weather. Arrivals were reported to be delayed at their departure origin an average of three hours due to snow and ice in the afternoon.

NYC's official emergency notification system published real-time notifications on its official Twitter account, urging the public to consider alternative routes while the city transit system was partly out of order.

Salt spreaders from the department of NYC Sanitation are working to keep the streets clear.

"Exercise caution during evening commute," Mayor of New York City Bill de Blasio? suggested, warning the roads could be "very slippery" at night.

According to National Weather Service, a winter weather advisory for NYC is in effect until 10 p.m. (0300 GMT, Friday), which means periods of snow will cause primarily travel difficulties.

The snow is predicted to change to a wintry mix of sleet and rain overnight.?