South Australian Forecast by Craig Brokensha (issued Monday October 14th)

Best Days: Later tomorrow South Coast, Mid Coast later Wednesday and Thursday morning, South Coast Thursday morning

Features of the Forecast (tl;dr)

• Moderate sized S/SW groundswell for tomorrow, fading Wed with fresh E/NE winds tomorrow, easing and tending N/NW late
• Moderate sized, inconsistent W/SW groundswell building Wed PM, holding Thu with variable tending SW winds mid-lat AM Wed (late S/SE-SE Mid Coast)
• NE tending E/NE winds down South Thu, E/SE tending N on the Mid
• Strong NW tending W/NW winds Fri with a building windswell on the Mid
• Easing swell Sat with SW winds, smaller Sun with morning E/NE-NE winds

Recap

The Mid Coast offered a great day of waves Saturday with Friday’s swell continuing in the 2ft range before fading back yesterday along with less favouring northerly winds.

The South Coast offered plenty of size but mixed conditions on Saturday, cleaner and great yesterday.

Today a background W/SW swell has continued to provide tiny waves on the Mid Coast, small and onshore down South.

This week and weekend (Oct 14 - 20)

We’ve got a fun week of waves across both regions with fairly persistent winds from the north-east along with a good sized S/SW groundswell for the South Coast tomorrow followed by W/SW groundswell Wednesday/Thursday.

The S/SW groundswell energy for the South Coast tomorrow has been upgraded with the polar low linked to it coming in stronger than forecast on Friday. A great fetch of severe-gale SW winds were generated in our southern swell window with the swell due to peak tomorrow morning to a good 4ft across Middleton with tiny surf inside the gulf.

Winds are a little funky and not ideal with a fresh E/NE’ly due down South, easing into the afternoon and then tending N/NW later. With this the afternoon/evening session is worth a look.

Wednesday is again a touch funky as early variable winds shift SW mid-late morning as a trough moves east, then back S/SE-SE late on the Mid. The South Coast will be fun early but easing from 2ft+ while on the Mid Coast, a new, inconsistent but strong, long-period W/SW groundswell is due to fill in from the Indian Ocean.

The source was one of the strongest, most prolonged lows of the year, moving slowly through the Southern Ocean in our distant western swell window. The system is now breaking down south-west of Western Australia and we should see some good but inconsistent levels of groundswell arriving through Wednesday, building into the afternoon ahead of a peak Thursday. The initial long-period energy probably won’t be ideal to get into the gulf (bottom friction and bathymetry steering), with it likely performing better on Thursday as it drops a few seconds.

Size wise the Mid Coast should build to 2ft on Wednesday afternoon with Thursday coming in at 2ft+. The South Coast should build to 3-4ft later Wednesday with Thursday coming in around a similar size across Middleton, fading Friday.

Winds on Thursday should be light, and local offshore across both regions (NE down South, E/SE on the Mid). Winds look to go more north inside the gulf and E/NE down South into the afternoon ahead of a trough and late W/NW-NW change.

This change will be associated with a deepening low forming over us and with this, stronger NW tending W/NW winds are due Friday with the easing levels of W/SW swell and some new, building windswell in the gulf.

The swell will be super localised and low quality, with the weekend seeing easing SW energy with strong but easing SW winds on Saturday, cleaner Sunday with a swing in winds around to the E-E/NE.

Longer term we’re looking at smaller, longer-range W/SW swells with winds from the north-east initially and then south to follow. More on this Wednesday.