Sydney, Hunter and Illawarra Surf Forecast by Ben Matson (issued Wednesday 22nd April)

Best Days: Thurs: Solid but steadily easing SE tending S'ly swell, improving conditions with light variable winds. Afternoon increase in new E'ly swell. Fri/Sat: fun small E'ly swell with offshore winds. Sun: freshening offshore winds and a small long range E/NE swell. Mon/Tues/Wed/Thurs: strong series of S'ly swells but with variable winds.  

Recap: Incredibly large, but extremely wind affected surf Tuesday. Hard to gauge surf size but all models (and my written forecast notes) dramatically undercalled this event - it’s hard to get an estimation on how much size eventuated because of the victory-at-sea conditions, but some of the photos and videos floating around the web suggest somewhere at least in the 15ft+ range between Sydney and Hunter coasts (tapering off smaller south from Sydney). If nothing else, the 3-4ft surf at Balmoral Beach was certainly a one-in-ten-year event (inline with stats from other weather parameters). Today we’ve seen a steady drop in size and winds went light W’ly for a brief period through the middle of the day, although have recently swung back to the south). Open beaches were still pushing 8ft+ this morning but are smaller this afternoon. However the swell is a lot more well defined than yesterday!

This week (Apr 23 - 24)

Our fun lovin' ECL is now dissipating into a broad trough encompassing the greater western half of the Tasman Sea. There’s still a strong E’ly fetch off its southern flank but that’s aimed exclusively into the Far South Coast and won’t influence many locations north of about Jervis Bay. 

As such, we’re looking at steadily easing SE swell through Thursday; early 4-5ft sets at open beaches but down to 3-4ft through the afternoon. 

However we have a new source of E’ly swell through Thursday afternoon and Friday, originating from a broad, slow moving NE infeed into the trough. In fact, this fetch - despite not be perfectly aligned for Southern NSW - will remain a swell source through into the weekend and it’s well worth capitalising on.

Thursday afternoon should see an increase into the 3ft range and it’s likely to hold this size through Friday (swell direction being mainly straight E’ly, due to the swell spread away from the more distant NE fetch). Locations south of Sydney should see a little more size too - I wouldn’t be surprised to see occasional 4-5ft bombs across NE swell magnets on the South Coast. However the Hunter Coast may see slightly smaller waves (than Sydney) due to the less favourable fetch alignment. 

Also, because we'll be seeing mainly sideband energy on Thursday and Friday, this swell will be rather inconsistent at times. So don't expect to rack up a high wave count. 

As for winds - Thursday looks reasonably good with mainly light variable flow all day in most areas. Most models are maintaining a weak low just off the Sydney coast during the day (within the broader trough) so this may instigate a moderate southerly at some locations to its south (i.e. across the Illawarra), and SE winds are likely in the Far South, but conversely winds should veer westerly to its north (i.e. Hunter region, maybe Sydney). 

Friday looks much better overall with a broader NW flow setting up across the coast, so this east swell should produce some nice beachies to finish the working week. Obviously, local banks pending…

This weekend (Apr 25 - 26)

Friday’s E’ly swell is expected to persist into Saturday although it will slowly ease in size. We may see a few 2-3ft sets early morning in Sydney (bigger on the South Coast, but smaller in the Hunter) however it’ll be on the way down - probably 2ft by the afternoon and very inconsistent. Conditions will be nice and clean with light offshore winds though.

As discussed on Monday, we’ve got a complex cut-off low that's expected to cross from South Australia, into Victoria and then the Tasman Sea over the weekend - eventually forming a broad Tasman Low - but it’s been delayed by a half day in the latest model runs. As such I don’t think we’ll see any new south swell until very late Sunday at the absolute earliest (more likely Monday). 

However, despite the Thurs/Fri/Sat mid-range E’ly swell being all but gone by this time, a brand new source of long range E/NE swell is expected to slowly build during Sunday. This will have originated from a broad tropical system located NE of New Zealand over the last few days. 

The bulk of its fetch has been aimed up into Northern NSW and SE Qld, but we should see a small spread of energy push down into Southern NSW. However, it will be extremely inconsistent. At this stage I’m not expecting much more than very slow 2ft sets at exposed beaches, but with freshening W’ly winds all day there should be some fun beach breaks on offer. 

Next week (Apr 27 onwards)

As this Tasman Low develops off the South Coast, we’ll see a strong S’ly fetch develop across its western flank, which will generate a strong southerly swell for Monday and Tuesday. South facing beaches should see set waves in the 4-6ft range however accompanying strong SW winds will limit conditions at some beaches (expect smaller but much cleaner waves at protected locations). Sunday's small E'ly swell should also keep ticking along in and around the 2ft range at remaining beaches.

A series of strong fronts/polar lows traversing the ice shelf (between Tasmania and New Zealand) through this period will maintain small long period southerly energy through the middle of the week however of more interest is another strong front that’s modelled to project north-east early the week, tracking east of Tasmania late Tuesday/early Wednesday and generating another strong southerly swell around next Wednesday and Thursday. 

As such, we’re looking at an extended period of strong south swell for the foreseeable future. More on this in Friday’s update.