Sydney Hunter Illawarra Surf Forecast by Ben Matson (issued Fri 18th April)

Features of the Forecast (tl;dr)

• Large, easing surf from Sat into Sun, clean early with AM offshores
• Small leftovers Mon/Tues
• Developing low off the coast Tues, bringing a punchy local swell Wed but with likely onshore winds
• New S'ly swell next weekend

Recap

Thursday saw fun waves across most beaches with early offshore winds and 4ft of SE swell, before freshening southerlies ruined things into the afternoon. Today’s seen another incredible XL swell across the entire East Coast, generally around the 10-12ft mark from the E/SE at most regions in Southern NSW however we’ve seen some impressive 15ft sets at some of the deep water bombies (see below). Winds have been light all day, early offshores with weak afternoon sea breezes. 

Queensie Bombie on fire this morning

This weekend (Apr 19-20)

The weekend’s conditions look pretty good, with light morning offshores and moderate afternoon NE sea breezes. We’re under the influence of a weak ridge of high pressure so weather conditions should remain relatively clear too. 

The large mid-latitude low in the central Tasman Sea - responsible for today’s very large surf - is slowly rotating clockwise, and by this evening won’t actually have a fetch aimed within our swell window. That being said, the sheer size and strength of the S’ly winds (on its western flank, see below) will ensure a healthy spread of energy back into the NSW coast. 

As for surf size, we’ve already reached the peak of this impressive event and so we’re looking at a steady drop in size both Saturday and Sunday.

However, Saturday will still kick off with relatively large surf in the 8ft range, and the swell direction will edge slowly towards the SE as the day progresses. Expect size to be down to around 6ft by the afternoon with a further easing from 4-6ft to 3-4ft on Sunday. Surf size inside southern corners will be a little smaller. 

And if anything, wave heights may taper off slightly in size with increasing southerly distance from about the Illawarra, due to a shorter fetch length and slightly bigger angular spread than locations further north.

Next week (Apr 21 onwards)

Small residual surf is expected Monday (2-3ft swell magnets early, smaller through the day) and Tuesday (1-2ft), with initially light variable winds on Monday at risk of freshening from the south, then south-east sometime from overnight into Tuesday as a weak trough off the coast consolidates into a closed system. 

Early indications suggest it probably won't reach the threshold of an East Coast Low, but don’t be surprised if this system is upgraded over the weekend. There's a nice warm SST pool off Southern NSW at the moment (2-3 degree higher than normal) which is ideally placed to fuel a developing surface low.

Any swell generated by this local system probably won’t arrive until Wednesday (unless the models speed things up over the weekend) and right now we’re looking at chunky onshore surf up to 6-8ft range with gusty SE winds. 

However, the model guidance is divergent right now (the US solution holding this low off the Hunter, whilst the European model sliding it up north), so the exact location of the largest surf could be anywhere between the Illawarra and North Coast.

This system will dominate our surf outlook for the rest of the week, with the next round of energy expected to originate from a frontal system pushing across Tasmania and into the Tasman Sea around Friday, providing a fresh southerly swell for the weekend.

Have a great Easter weekend, see you Monday!