South Australian Surf Forecast by Ben Matson (issued Monday 24th October)

Best Days: Tues AM: fun clean surf down south. Thurs/Fri: solid building swell down south, and some good waves on the Mid with light winds across both coasts. Sat: more W/SW swell for the region, producing good waves on the Mid under a NE breeze. Clean down south. Sun: morning options with early offshore winds. 

Recap: Mainly onshore winds over the weekend didn’t generate any great surf along the South Coast, and wave heights remained small across the Mid Coast though conditions were very clean with light offshore winds. 

This week (Oct 25th - Oct 28th)

A new groundswell is expected to push through SA waters this afternoon, but it’s yet to show at the CdC buoy and there’s no sign of an upward trend on the surfcams either (this is expected somewhat; the swell isn’t due until very late).

In any case, this new swell should produce a good day of waves at Victor on Tuesday with surf size building a little more from today, maybe some inconsistent 2-3ft sets off the point at Middleton, bigger out at Waits and clean under a freshening N’ly tending NW breeze. Tiny surf is expected on the Mid and these winds won’t do it any favours either. Easing surf is then expected into the afternoon. 

Wednesday looks pretty ordinary with a weak front clipping the state, pushing W’ly winds to the SW, and no new swell to speak of. Expect very small lacklustre conditions on the Mid Coast and small, cross-shore tending onshore surf down south. 

Thursday is shaping up to deliver great waves though.

Craig’s Friday notes detailed a significant Southern Ocean low tracking through out far swell window over the weekend, and the models have maintained this system very well in the latest runs. The leading edge of the expected long period groundswell (18+ seconds) is expected approach the coast around dawn on Thursday, so the morning will probably start off undersized across most coasts, ahead of a strong increase throughout the day, peaking overnight Thursday. 

This swell source is quite broad, strong and it held within our swell window for a decent length of time so we should see solid lines across most coasts. The Mid Coast should see surf size building to 2-3ft through the afternoon (biggest late in the day) and along the South Coast we’re looking at afternoon 4-5ft surf at Middleton, reaching 6ft+ at some of the more reliable swell magnets that focus long period swell efficiently.

Surface conditions don’t look too bad either; a weak high pressure ridge should create light and variable winds. Note: this means that the wind can come from any direction - i.e. onshore - but it shouldn’t be too strong, so surface conditions should be reasonably good.

What I like most about this swell event is that the system responsible for it weakens only slowly through its passage under the continent, which means the backside of the peak - on Friday - will ease only slowly in size. And with a weak ridge of high pressure creating light variable winds and sea breezes, Friday morning should deliver some excellent waves across the coast. 

Victor should maintain early sets anywhere between 4ft and 6ft (depending on exposure), and the Mid Coast may very well see clean glassy conditions with occasional 2-3ft sets before the tide drains out (high is at 4:30am, low is around 10:30am). The afternoon may produce a small push on the incoming tide but it will probably be a little smaller than Thursday afternoon.

Winds are looking excellent on Friday, light and variable again with a NE tendency through the morning, probably swinging light to moderate SE into the afternoon across the South Coast and S’ly across the Mid Coast. 

It is worth noting that another groundswell - with a little more west in its direction - is due to arrive overnight Friday. There is a chance it could arrive very late afternoon across the Mid Coast (providing a bigger boost) but I’ll update these thoughts on Wednesday.

This weekend (Oct 29th - 30th)

Whilst all of the late-week action is happening, another series of fronts will have reared up south-west of WA, generating new W/SW tending SW swell for our coast.

As mentioned above, the leading edge of this next swell is due to push through on Friday evening, and should provide some good waves down south throughout Saturday under a freshening N/NE breeze. The swell direction won’t be great for Victor but we should see a rebuilding trend back into the 3-4ft range at Middleton, with larger waves at Goolwa, Waits and Parsons.

The Mid Coast is expected to see a decent push from this swell on Saturday but I’m a little concerned about the potential strength of the N/NE flow. Models have this around 12-17kts which will be OK if it’s straight NE (a reasonable possibility) but if it veers more to the north there may be some problems. 

Either way, I like the track of this low and core winds are expected to maintain strength as it pushes through the swell window, so we should see 2-3ft sets across the Mid Coast on Saturday. Well worth keeping a close eye on things for.

Saturday’s W/SW swell will then ease a little into Sunday and local winds are tricky to pin down due to an approaching cold front. It’s likely to strengthen NW winds ahead of a gusty SW change late in the day but there’s little confidence in the timing right now. Once the change pushes through, we should see a building stormy across the Mid Coast though this may happen too late to benefit surfers. 

Next week (Oct 31st onwards)

Sunday’s late change will weaken through Monday but we’ll be in a post-frontal SW airstream so expect bumpy 2-3ft surf on the Mid Coast and choppy 3-5ft surf down south. 

Surf conditions are expected to improve rapidly through the middle of the week as a broad high pressure ridge sets up camp across the state, however this may also shut off the supply of swell to the region, resulting in smaller conditions best suited to exposed coasts. 

I’ll have more on that in Wednesday’s update.