Damaging wind gusts of up to 100 km/h are possible in Newcastle on Thursday night, as the NSW Bureau of Meteorology warns of a ow pressure system deepening in the Tasman Sea and moving south.
The bureau has warned of abnormally high tides, hazardous surf and potentially dangerous beach conditions in the Hunter region due to the low pressure system, which is producing strong winds in combination with a high pressure ridge dominant over the Great Australian Bight.
In an alert put out in the early hours of Thursday, the BoM identified Newcastle, Taree, Port Macquarie, Sydney, Wollongong and Batemans Bay as the locations that could be affected.
The recent and ongoing adverse weather has forced the postponement of Maitland's Hunter Valley Steamfest from next weekend until July 30 and 31.
Maitland council said the recent wet weather had "instigated a number of issues outside everyone's control", starting with a significant embankment failure at Picton, south of Sydney, severely affecting the main tracks and branch line, isolating steam locomotives 3801 and 6029, which were two of the key attractions for this event.
"ARTC has worked tirelessly to find a solution to the situation however, have now confirmed that the extensive works required to repair the heritage branch line can't be completed in time for the delivery of the locomotives for Steamfest," the council said.
Meanwhile, the Bureau of Meteorology says abnormally high tides could cause local inundation between Seal Rocks and South West Rocks and "very heavy surf" - with waves higher than five metres - could cause damage and erosion from Thursday afternoon and into Friday.
A warning has also been issued for expected gale winds on the Hunter coast, Sydney enclosed waters, Byron coast, Coffs coast, Macquarie coast, Sydney coast, Illawarra coast, Batemans coast and Eden coast.
Between 9am on Wednesday and 8am on Thursday, Cooranbong at Lake Macquarie recorded 25mm of rain, Maitland had 17mm and Williamtown had 14mm, while only 3mm was recorded at Nobbys.
