Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Monday 26th December)

Best Days: No great days though there'll be small beachies all week and into the weekend.

Recap: Small peaky swells from the E/NE and NE with sets between 2ft and very occasionally 2-3ft on the more favourable parts of the tide. Early light N’ly winds freshening from the N/NE each day.

Classic summer scenes at Maroubra this afternoon with a peaky NE swell in the water

This week (Dec 27th - 30th)

A stationary blocking high in the Tasman Sea will direct N/NE winds across Southern NSW right through this week and into the weekend. In fact, aside from shallow, temporary breaks in this pattern we would appear to be looking at an extended period of northerly winds across the coast for the next couple of weeks.

The current small long range E/NE swell will ease over the coming days, leaving our primary swell source from the local NE fetch. Wave heights will ebb and flow in sync with the nearby wind field; wave heights should maintain a steady trend in and around the 2ft range all week with a few periods of bigger surf towards 2-3ft as the fetch briefly muscles up. Model guidance currently suggests these heightened periods will be Tuesday and Thursday mornings, though in reality we could see bigger pulses at almost any time. 

Nevertheless, with winds out of the N/NE, they’ll be lightest in the mornings and this is when the best conditions will be present each day. Overall it’s a fairly standard run of summer surf and there’ll also be an increased chance of bluebottles and cold water upwelling (so, you may have to unpack the short arm steamer within a few days).

Last week, I discussed at length a promising tropical system developing near New Caledonia that had the potential to generate a larger E/NE swell for the second half of this week. Unfortunately, the latest model guidance has eased back the strength of this system and kept all developments north of Byron Bay latitudes, which means its capacity to generate decent surf for Southern NSW is greatly diminished. We may see some small trade swell off the supporting fetch through the Northern Tasman Sea later this week but it’ll be smaller than the pre-existing short range NE windswell.

This weekend (Dec 31st - Jan 1st)

Nothing major expected this weekend.

Small NE windswells will persist into Saturday, and a trough moving over Southern NSW should bring about a period of lighter, more variable winds (with thundery activity due to the accompanying unstable airmass). Exposed beaches should see surf size somewhere just north of 2ft but less than 3ft, and it’ll be smaller at south facing beaches, much the same as we’re expecting all of this week.

A southerly change trailing the trough may push into Sydney on Sunday but no great strength is expected so I’m doubtful that there’ll be any meaningful size increase in the surf department. The most likely outcome is a continuation of slightly smaller NE and E/NE swells, around 1-2ft at most open beaches, but with moderate southerlies across the coast.

Next week (Jan 2nd onwards)

There’s noting significant standing out in the long term outlook.

The most likely scenario is for a return to NE winds next week as a new high develops in the Tasman Sea, which would bring about small local windswells.

A small southerly swell may push up the coast early in the week, originating form the parent low to the weekend’s southerly change but current indications are that it’ll be small and lacklustre. 

Model guidance also has a strong Southern Ocean low pushing into the lower Tasman Sea later Wednesday and Thursday (which would result in a strong south swell later in the week) but I’m not very confident on this scenario right now.

Let’s wait and see how things are looking on Wednesday.