Monster swells are expected to batter the New South Wales coast today with beach-side residents warned to brace for dangerous conditions. A cold front crossing the Tasman Sea will generate a large and powerful southwesterly swell. Damaging surf conditions, with significant wave heights of five to six metres, are likely to develop from this morning and may produce beach erosion for south to southwest facing zones. Conditions are expected to ease later tonight or early tomorrow morning. There is a warning for hazardous conditions for Byron Coast, Coffs Coast, Macquarie Coast, Hunter Coast, Sydney Coast, Illawarra Coast, Batemans Coast and Eden Coast. Surf conditions are expected to be hazardous for coastal activities such as rock fishing, boating, and swimming in the following areas.