DAMAGING winds are expected to batter the NSW coast and residents are being warned to secure their homes and vehicles.

The Bureau of Meteorology today issued a severe weather warning for the Sydney, Illawarra and Hunter regions.

South to south-westerly winds averaging 65km/h, with peak gusts of 90km/h, are expected to hit tonight and last through tomorrow morning.

The State Emergency Service says vehicles should be moved under cover and away from trees.

Residents should also secure loose items around their homes, yards and balconies and stay clear of fallen power lines.

Meanwhile, the Great Western Highway has been closed in both directions at Yetholme, between Lithgow and Bathurst due to snow.

"Motorists are advised to avoid the area," Transport NSW said.