Sydney Hunter Illawarra Surf Forecast by Steve Shearer (issued Fri 16th May)

Features of the Forecast (tl;dr)

• Last day of small clean E swell and light winds Sat
• S groundswell in the water through Sat, persisting into Sun
• Sizey mix of S swells likely Sun fresh/strong S winds
• Deep trough/low forming Mon with strong SE winds and swells
• Surf remaining elevated from the E/SE-E through Tues into Wed, slowly easing Thurs
• Winds strong Tues, moderating Wed and tending offshore Thurs
• Possible spike in new S swell Fri
• Dynamic pattern persists so check back Mon for latest revisions!

Recap

Small E’ly swells have kept  a surfable signal going on the beaches with yesterday seeing 2-3ft surf under light offshore breezes tending to variable winds in the rain. Similar today, with the occ. 3ft set but mostly 2ft and a light/variable flow- not perfectly clean with a  bit of leftover bump on it as a low pressure trough moves down the coast, but definitely workable. Much more dynamic outlook ahead.

Still some fun beachies about in the rain

This weekend (May17-18)

No great change to the weekend f/cast. The low pressure trough moves away Sat and leaves a weak ridge with a lingering S’ly flow. Strong confidence early winds will be from the land (W-W/SW) before slowly clocking around to light S-S/SE breezes. Just a few leftover E’ly swells trains in the water for protected spots. There’s a powerful polar low slow moving under the continent with multiple fetches operating well to the SW of Tasmania. Most of the swell is heading up the pipe for South Pacific targets but we will see long period S swell wrap showing through Sat (arvo looks a better bet). Winds won’t be ideal for S facing beaches but some 3-4ft sets are expected and outliers at deepwater adjacent reefs are very possible. 

That swell holds into Sun at similar or just elevated levels but winds will steadily increase from the S on Sun as remnants of the trough get captured by a strong ridge of high pressure building in from the Bight. Morning breezes from the SW will tend S’ly and steadily freshen through the mid/late morning, tending more S-S/SE later in the a’noon at fresh/strong paces. As well as the S groundswell we’ll see building levels of raw short range S swell, pushing up from 2-3ft into the 3-5ft range by close of play. Spots out of the S’ly wind will be considerably smaller. 

Next week (May 19 onwards)

We’ve got good model agreement now that through Mon we’ll see a deep trough develop from the Coral Sea down to a terminus somewhere on the MNC to lower North Coast with good odds we will see a surface low develop at that terminus. Areas to the south of that trough/low will see strong SE-E/SE winds develop, with those winds extending into a powerful fetch through the Central Tasman. Areas to the north should maintain a light offshore outflow from the trough/low. 

If this holds true (we could still get a shift in the position of the trough/low) we’ll see some windy, large days to start next week.

Mon is likely to see fresh/strong SE winds and surf from the SE-E/SE in the 6ft range. 

Likely very similar with surf even bigger as the fetch draws out, with swell direction tending more E’ly. That should allow plenty of swell energy into the more protected spots which will be required to get some wind protection.

Wed looks interesting. A trough line developing along the south coast and extending up towards the Hunter may offer chances of light winds or even some offshores. Swell remains strong from the E with at least 6-8ft of E swell in the water (possibly at the upper end of that scale). Winds at a minimum should ease right back Wed so pencil it in for a day of very solid surf, even if not perfectly clean. 

Models suggest the trough/low complex will move south and even SW towards the south coast later next week- which would see the winds shift SW through Thurs and then wash out to light/variable breezes Fri morning before stiff S’lies.

Swells will ease slowly as the fetch into the low devolves into a broad but weakening infeed. 

Still lots of size on Thurs in the 5-6ft range, possibly smaller Fri from that source, with potential for a spike in new S swell as the return flow on the low builds a S’ly fetch along the Southern NSW coast and into the Tasman (see below). 

Lots of water to flow under the bridge before we get there, so expect revisions when we return on Mon.

Model runs have also toyed with the idea of more low pressure development in the Coral Sea or Tasman, although latest runs have back off on that possibility. 

We’ll see how it looks when we come back Mon.

Until then, have a great weekend!