A strong low pressure system making its way east over the Tasman Sea is directing very large swells towards the NSW coast.

Having crossed far southeastern Australia on Saturday, the low has been gathering strength as it makes its way over the Tasman Sea. The system has gone from bringing NSW powerful winds and alpine snow, to very large waves pounding the coast.

Large waves are already reaching the NSW south coast, and on Monday the wave heights will peak there and all the way up the coast. Waves in excess of 10 feet are a high chance for parts of the NSW coast exposed to southerly swells on Monday, continuing into Tuesday as the swell train roars up the coast.

Offshore buoys are likely to record maximum wave heights well above what breaks along the beaches. 2-3 metre waves have been recorded already on Sunday, and could at least be triple that come Monday afternoon.

The huge surf will likely cause beach erosion, and will be extremely hazardous for coastal sports such as surfing and fishing. A Hazardous Surf Warning is current for Coffs Coast, Macquarie Coast, Hunter Coast and Sydney Coast on Sunday, and all NSW coasts on Monday.