South Australian Surf Forecast by Ben Matson (issued Wednesday 26th October)

Best Days: Thurs PM/Fri: solid, but very inconsistent new groundswell at Victor with OK winds Thurs afternoon, becoming great early Friday with light variable winds. Plenty of good waves on the Mid Coast too later Thurs and thru' Fri. Sat: renewal of W/SW swell with great waves on both coasts. Sun: good ol' Mid Coast stormy; small window down south early morning. Mon/Tues/Wed/Thurs: building S/SW swells for Victor, looking large and clean for Wed, easing Thurs. 

Recap: Tuesday’s swell came in a little under forecast expectations though conditions were clean down south with fresh offshore winds. The Mid Coast remained tiny. Today we’ve seen very small conditions down south and fresh onshore winds, with a tiny boost on the Mid Coast though still the better part of unsurfable.

This week (Oct 27th - Oct 28th)

We’ve got some great waves ahead right across the state.

The leading edge of a new long period SW groundswell is expected to reach the state sometime in the early hours of Thursday morning. 

However the bulk energy from this event will be located some 12-18 hours behind the forerunners so we’re unlikely to see an increase across most coasts until late morning or lunchtime, with the afternoon showing strongly ahead of an overnight peak and then levelling trend through Friday.

Winds won’t be fantastic for Victor, but they won’t be too and either. Today’s front will pass quickly to the east, leaving us in a light variable airstream that could swing NE for a period throughout Thursday morning, though there’ll probably still be some lumps and bumps on the surface. It should get better during the day even if we see light onshores after lunch. 

As for size, I’ve slightly pulled back my expectations for this event as satellite winds have come in a little under the model guidance. Surf size will start off small at Victor, but build throughout the day towards a late peak in the 3-5ft range at Middleton, with bigger sets at exposed beaches and reefs that efficiently focus these kinds of long period swells.

On the Mid Coast, we’ll start off very small but the afternoon should see a push to somewhere between 2ft and maybe 2-3ft, and conditions will remain clean for the most part with light SE winds tending S’ly during the day.

Please note: due to the distant swell source, set waves will be VERY inconsistent at all coasts, so bear this in mind as it’ll probably limit your wave count. 

Thursday's new swell should level out into Friday, with the Mid Coast likely to see lully conditions with occasional 2ft to maybe 2-3ft sets on the more favourable parts of the tide. Light variable winds and sea breezes should maintain great conditions.

Down south we’ll also see light winds and a similar sized swell as per late Thursday, with very inconsistent 3-5ft sets at Middleton and bigger waves at the focussed reefs and beaches. Well worth your time and attention.

This weekend (Oct 29th - 30th)

No changes to the weekend forecast. We’ve got some great waves ahead, with most coasts likely to produce the goods on Saturday ahead of a gusty onshore change throughout Sunday. 

A strong series of fronts moving through the Southern Ocean on Thursday and Friday will generate a new W/SW swell that’s expected to push through at some point early Saturday. The models have firmed up this system a little since Monday’s notes so confidence for the Mid Coast outlook has increased a little. However, the is still some risk that winds will veer form the NE to the N during the day, which may create unwelcome lumps. 

Wave heights should rebuild back into the 2-3ft range during the day, possibly a little undersized early morning but with a chance for a few stray bigger waves through the afternoon at the reefs. Let’s hope winds remain favourable all day because the weather system generating this swell is strong and broad, positioned in a good part of our mid range swell window and displaying a healthy storm track.

The slightly higher westerly component in the swell direction will cap wave heights at Victor Harbor on Saturday, however all beaches will be clean under the NE tending N’ly breeze. We should see occasional 3-5ft sets at Middleton throughout the day (possibly a slight lag at dawn) and once again, exposed beaches and well focused reefs should see bigger bombs. 

On Sunday, surf size should maintain across both coasts - in fact a second pulse of groundswell with slightly larger peak periods is expected during the day from the same system - but a cold front will approach the coast, strengthening NW winds ahead of a gusty W/SW tending SW change. These winds should also add another foot or two on to the Mid Coast’s groundswell component. 

So, it looks like we’ll see a decent Sunday stormy on the Mid Coast, and the only options down south will be at dawn before the onshores hit.

Next week (Oct 31st onwards)

Next week looks really promising on the synoptics, mainly for the South Coast. Sunday’s change is expected to renew short range W/SW tending SW swell for the coast for Monday but local winds should ease a little from the west. It’ll still be bumpy across the Mid Coast but we’re likely to see 2-3ft surf across most breaks. 

In fact, it looks like we’ll see an elongated fetch with embedded fronts anchor itself within Victor's near to mid S/SW swell window through the first half of the week (see right). This is expected to deliver three or four days (Mon ‘till Thurs) of building S/SW swell across the South Coast, with mainly fresh W’ly winds at first, occasionally W/NW for periods in the mornings. 

At this stage Wednesday looks like it’ll see the biggest waves from within this synoptic progression, with solid 6ft+ surf across the coast and current indications are that the westerly stream will have eased by this time, allowing light offshore winds to prevail. Thursday should also see offshore winds with solid but slowly easing surf. 

This storm track will develop a little too far to the east to favour the Mid Coast (as most of the swell will be shadowed by Kangaroo Island) however we’ll probably see a foot or two sneak in through the gulf during this period. 

Let’s take a look at the broader long term picture in Friday’s update.