Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Monday 13th June)

Best Days: Tues/Wed/Thurs: fun mix of east and south swells with mainly clean conditions (only exception Wed AM with a brief S'ly change). Fri: strong long period S'ly swell with offshore winds. Sat: easing S'ly swell with offshore winds. Mon: potentially a very large swell thanks to a possible ECL.

Recap: Clean easing leftovers padded out much of Saturday under an offshore breeze. A new south swell filled in overnight Saturday, providing 4-5ft waves across south facing beaches early Sunday, before easing a little into the afternoon. The expected fresh southerly airstream generally held back, allowing for early light offshores ahead of a moderate southerly breeze at some locations throughout the middle of the day, and then back to a late afternoon offshore. As such, despite surf size being within forecast expectations, conditions were better than expected. Monday dawned smaller with easing S’ly swell (3ft) and some small leftover E’ly swell (1-2ft). A new pulse of E’ly swell expected to arrive today has yet to show any definitive signs but it’s (surely!) not too far off. 

This week (Tuesday 14th - Friday 17th)

We’ve got plenty of surf expected this week.

Although the new E’ly groundswell from the eastward retreating Tasman trough - positioned north and north-east of New Zealand last Friday - hasn’t arrived yet, I’m still very confident it’ll rock up soon.

The swell from this source will be very inconsistent but we should see 2-3ft+ sets at most open beaches through Tuesday, before easing and levelling slightly into Wednesday and holding through Thursday and Friday (inconsistent 2ft+ down to 2ft during this time frame).

Also in the mix over the majority of this week will be some sideband trade swell from a strong ridge currently occupying the northern Tasman Sea and Coral Sea. This fetch is pointed generally away from our region but it covers quite an impressive stretch of our northern swell window, and therefore we should see some small energy spread back down our way. It certainly won’t be as big as the long range E’ly swell but it should fill in the (rather lengthy) gaps nicely with small peaky sets. 

Local winds look pretty good for the first half of the week - light offshores Tuesday, with a shallow S’ly change on Wednesday unlikely to deliver much strength to the coastal margin - maybe just a few hours of moderate to fresh winds early Wednesday morning, before becoming variable into the afternoon. So it should be pretty reasonable on top. NW offshores will then return for Thursday and Friday.

The other swell source(s) to look forward to this week is a series of long period southerly groundswells, generated by an active frontal progression through the Southern Ocean, south of Tasmania.

In general, the storm track will be quite zonal - west to east - which means it won’t be aimed very well within our swell window. But the sheer breadth of the resulting fetches and their considerable strength (up around 50-60kts at the core of the primary system, later Tues/Wed) means we’ll see some very impressive swell periods pushing up the coast, possibly in excess of 19-20 seconds. 

Several small groundswells will ebb and flow between late Tuesday and Thursday; no major size is expected but inconsistent 2-3ft sets at exposed south swell magnets are quite likely during this period. However, Friday morning is when we’re expecting to see the main event from this series, displaying the largest waves and longest periods. South facing beaches across the Sydney region should see occasional 3-4ft+ bombs, whilst the Hunter coast - which always does well under these long range southerly swell - should see sets pushing 4-6ft at times.

Keep in mind that beaches with less southerly exposure will be much smaller, however they’ll also be picking up the tail end of the dual east swells too.  

This weekend (Saturday 18th - Sunday 19th)

Looks like a small weekend of residual swells ahead.

A deepening low is expected to begin formation south of Tasmania around Thursday, but although we’ll see surface winds reach 60kts or more, these developments will mainly happen as the low pushes well and truly outside of our swell window. So for now I’m excluding this as a major swell source for the weekend.

A weak front may push into the lower Tasman Sea later Friday, generating a small short range swell for later Saturday or Sunday but again, no major size is currently expected. 

As such, we’re really just looking at leftover E’ly swell and fading S’ly swell (from Friday’s impressive pulse). Saturday morning may see some leftover 2-3ft sets at south facing beaches (bigger in the Hunter) but it’ll become smaller as the day progresses. The east swell will probably be contributing even smaller, less consistent levels of energy by this time too. Conditions will however be nice and clean with offshore winds.

Sunday looks a little smaller again, and local winds are expected to become tricky as the early stages of what appears to be a developing ECL starts to unfold across the coast. So right now, Saturday is certainly the pick of the weekend for the surfing community.

Next week (Monday 20th onwards)

Jeez, the models are looking quite dynamic for early next week.

We’ve got quite a primed environment too, with positive SSTs anomalies in the western Tasman Sea (up to 4.5 degrees off the South Coast, see image to the right), a developing surface trough over the eastern states (dragging lots of moisture from Qld) and an approaching upper level cold pool from the west. And also, a potentially blocking high over New Zealand longitudes. 

These are crucial ingredients for an East Coast Low to develop, and seeing that the models have slowly started to converge on this scenario over the last few days, it’s all starting to look like Monday and Tuesday will see very large surf and very windy conditions across the coast. 

It’s too early to start pinning down specifics but for now we’re looking down the barrel of another major swell event for Southern NSW. More on this in Wednesday’s update.