Weather

Large hazardous surf to hit the NSW coast

Felix Levesque, 12 January 2020

Sizeable long period swell will bring dangerous surf to much of the New South Wales coast tomorrow.

 

Following a vigorous, gusty southerly buster very early on Saturday morning, strong sustained southerly winds have been generating large shorter period swell. Yesterday, significant wave heights reached 3.3 metres in Sydney through the morning. This southerly swell had a relatively short period of 7-10 seconds and was accompanied with strong southerly winds, bringing poor surf across much of the southern and central NSW coast.

 

While conditions have somewhat improved today under slightly weaker winds and a more tamed 1.5-2 metre short period windswell, a building groundswell will bring dangerous conditions tomorrow.

 

A deep low pressure system far into the Southern Ocean located more than 2500 kilometres south of Sydney is generated an extended area of wind, facing generally towards the Tasman Sea and the NSW coast. This fetch of strong sustained winds, reaching 70-80km/h, and gusting near 90-100km/h has been building up wave height and creating a deep reaching ground swell (wave energy reaching 10’s of metres into the ocean). The swell is currently hurling itself towards our coastal parts of Tasmania, NSW, Queensland, New Zealand and towards the South Pacific Islands.

 

Monday will see a growing long period southerly groundswell with wave period at Sydney reaching possibly 17 seconds in the early hours of the morning, and wave heights in the 1-1.5 metre range. Although the wave height is smaller than the previous windswell on Saturday, the long period of this swell means each wave is carrying much more energy, bringing dangerous waves across beaches, headlands and rock-platforms all across the coast.

 

In Sydney, the swell should remain in the 1-1.5 metre range, while the period gradually drops to 14-16 seconds throughout Monday. Sadly for any surfriders, moderate onshore winds should hinder otherwise excellent conditions. With the surf across southerly exposed beaches expected to reach the 4ft range, with the odd 5-6ft set, wave riding should be left to experienced riders. Large swells contain huge amounts of board and body breaking energy and large rip currents form from all the water moving in and out of beach zones.


A hazardous Surf Warning is currently in place for Monday for all coasts between and including the Eden Coast to the Coffs Coast. Rockfishers and people should avoid rock-platforms exposed to this swell, while boaters should consider the conditions and possibly delay any outing at sea while the swell brings dangerous surf across ocean bars and shallow waters. The hazardous surf should also remain into Tuesday Morning. For information on all current warnings, visit: https://www.weatherzone.com.au/warnings.jsp