Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Friday 27th April)

Best Days: Sat/Sun/Mon: plenty of swell but dicey with fresh S'ly winds at times. Tues: strong, easing SE swells with good winds in the morning. Wed: smaller but cleaner.

Recap: Thursday offered fun clean peaky surf in the morning ahead of a developing southerly change that’s written off  most open beaches from Thursday afternoon through much of today. We have seen a building S’ly windswell to 3-4ft in its wake but quality isn’t particularly high.

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This week (April 28 - 29) 

There’s been an upgrade in strength and a forward time-shift with regards to the developing low pressure system in the north-eastern Tasman Sea.

The current southerly change is interacting with a trough well south of New Caledonia, and is expected to broaden and deepen a low pressure system west of Auckland tonight, with a wide fetch of southerly gales on its western flank.

Unfortunately, these winds are aimed well and truly away from Southern NSW. In fact, they’re even off-axis for Northern NSW, though we will still see plenty of size across this region. But because the low has evolved along an existing strong ridge that’s already generating S/SE swell for the region, we should see an appreciable amount of size push into Southern NSW. 

Unfortunately, the outlook for the entire weekend is still marred by persistent S/SE winds, thanks to the presence of the coastal ridge. A small front will enter the lower Tasman Sea early Sunday, and apart from a brief window of lighter winds in the morning (likely south from Sydney) we’ll see freshening southerlies throughout the day again. 

Had this low been aimed favourable towards our coast, we’d be looking at easy 8-10ft sets at some exposed spots. Unfortunately, its poor alignment means that wave heights will be shaved off considerably as you track south from the Far North Coast, and the end result will probably be somewhere around 3-4ft+ across most open beaches (mainly south facing) on Saturday, up to 4-5ft+ across the Hunter. Wave heights are likely to be a little smaller south of the Illawarra, though winds should be a little lighter too.

Sunday should see a little more size as the wavelength draws out, around a foot or so, maybe a little more if we're lucky. Southern corners will be smaller - though not as small as we usually see under southerly swells - and cleaner with these breezes. 

Next week (April 30 onwards)

As the Tasman Low evolves over the weekend it’ll aim the primary fetch more around to the east, though without quite the same strength expected this evening. This will generate a series of better quality, though slightly smaller SE thru’ E/SE swells for Monday and Tuesday. 

Unfortunately, a rebuilding ridge along the coast on Monday will maintain fresh southerly winds and consequently keep surf conditions well below spec - there is a chance for an early period of SW winds, but model guidance is suggesting the ridge will be quite firm so if it eventuates, it’ll probably be at just a few spots. 

As for size, most open beaches should see size in and around the 4-5ft mark on Monday, with perhaps some bigger surf near 5-6ft  at some exposed locations, such as parts of the Hunter coast. Size will ease a little into Tuesday but should remain quite strong. Local S’ly winds will also ease right back on Tuesday, allowing a broad region of early SW or event W/SW winds. 

The long term outlook slowly moves this system out of our swell generating window, and therefore leads to a decrease in size throughout the second half of the week with generally light winds. 

There are hints at new swell possibilities for the extended period, with the remnants of this weekend’s Tasman Low lingering on the other side of New Zealand, but possibly just far enough north to sit inside our eastern swell window.

Otherwise, a developing trough along the western Tasman Sea has potential for a NE swell later next week or into the weekend, following by a return southerly swell early in the following week as this system clears to the east.

It's a very dynamic period indeed. Have a great weekend, see you Monday!