Sydney ushers in winter with coldest day of the year as two trucks crash on icy roads

New South Wales has ushered in winter with the coldest day of the year in Sydney and snow falling on the central tablelands.

The low temperatures have created dangerous conditions on the roads with ice and snow causing two trucks to slide off the Great Western Highway near Diamond Swamp Road early Wednesday morning. Motorists in both directions were being warned to avoid the highway.

Temperatures were expected to hit 15C on Wednesday in the city, but the wind chill is making it feel a lot colder.

The state is being lashed by a cold front and low-pressure system that has moved in from South Australia bringing with it rain, snow and furious winds.

Western Sydney residents faced gusts up to 100km/h overnight with the Bureau of Meteorology (BoM) issuing a severe weather warning for damaging winds of 60-70km/h on and east of the Great Dividing Range.

Several areas through the Illawarra have also recorded wind gusts in excess of 90km/h, while Newcastle, Sydney, Wollongong, Nowra, Armidale, Canberra and Goulburn are all likely to cop severe weather.

The Great Western Highway was closed between Marrangaroo and Kelso after two trucks came off the road in separate incidents.

An image shared by Bathurst MP Paul Toole showed one of the trucks on its side surrounded by ice and snow.

“At both locations, trucks have slid off the highway due to snow and ice,” he said.

“We expect the highway to be closed for a number of hours and all detour routes are impacted by snow.”

The BoM said very windy and cold conditions were likely to persist throughout the day as a high-pressure system moves over western parts of the state.

The NSW snowfields will open early this weekend, with Thredbo resort reporting 19cm of snow falling over the last six days and Perisher recording 22cm over the same period.

Saturated ground from the drenching NSW copped over the last few months brings an increased risk of gusting winds toppling trees and powerlines, particularly along elevated terrain.

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The SES has responded to about 1,400 calls for help since Monday with falling trees causing the greatest hazard.

Sydney is expected to record its coldest day of the year on Wednesday, with only 10 June days in the previous four years with temperatures below 15C.

On 20 April, a temperature of 14.9C was recorded, but Wednesday’s wind chill factor was expected to make it a lot colder.

The plummeting mercury comes after Sydney recorded its wettest autumn on record.

The state capital’s 1,008.4mm between March and May is the city’s highest autumn total in records dating back to 1859, said Weatherzone meteorologist Ben Domensino.

The January to May period was also Sydney’s wettest on record.

With AAP