South Australian forecast by Craig Brokensha (issued Monday April 7th)

Best Days: South Coast tomorrow morning and Wednesday morning, South Coast Thursday, Mid Coast Friday afternoon and Saturday morning, South Coast all weekend

Features of the Forecast (tl;dr)

• Moderate sized reinforcing S/SW swell tomorrow AM, easing with variable offshore winds ahead of relatively weak sea breezes
• Easing swell Wed with N/NE tending E winds
• Moderate sized S/SW groundswell filling in Thu (undersized early), easing Fri
• Moderate N/NE tending N/NW winds Thu, with S/SE winds Fri down South (variable on the Mid)
• Moderate sized W/SW-SW swell building Fri PM, peaking Sat, easing Sun
• N/NE tending weak sea breezy winds Sat/Sun

Recap

Firstly just a heads up that surfers are still reporting eye and throat irritations so the algal bloom isn’t totally gone yet.

The weekend was a mixed affair with early onshore winds across the South Coast Saturday quickly backing off and swinging variable offshore through the morning, creating improving conditions along with a mix of moderate sized swells.

The Mid Coast was glassy and a little lumpy but back to 1.5ft following Friday’s pulse.

Into yesterday, our new mix of SW swells started to fill in and conditions were great across the South Coast with building sets to the 6ft range into the afternoon, best before lunch (with less size) before winds shifted more westerly and then onshore later.

The Mid Coast offered a window of clean conditions with some nice new swell lines before the change moved through.

This morning we’ve got easing levels of large SW-S/SW swell with early variable winds across both coasts and surf to 1-2ft inside the gulf and 4-6ft down South.

Decent options this morning under variable winds

This week and weekend (Apr 8 - 13)

The strong and significant Southern Ocean frontal progression linked to yesterday’s and today’s swell still has legs, with most of the main activity passing, leaving weaker trailing storms in its wake.

This should provide a slow easing trend over the coming days, with a fun reinforcing pulse of swell energy due overnight tonight and into tomorrow morning out of the S/SW.

This is a moderate sized, mid-period swell, generated by a strong fetch of SW winds projecting up and into Tasmania yesterday afternoon and evening.

Middleton should still be around 4ft to occasionally 5ft tomorrow morning with 1-1.5ft sets across the Mid Coast under variable offshore winds ahead of sea breezes.

A light N/NE offshore is then due on Wednesday morning as the swell backs off from 3ft to occasionally 4ft across Middleton. Sea breezes both tomorrow and Wednesday look relatively weak, but the mornings will be best.

Into Thursday, we’re expecting a fun pulse of reinforcing S/SW groundswell, generated by a low that’s currently south of Western Australia, with it forecast to generate a tight but good fetch of gale to severe-gale W’ly winds on the polar shelf.

The swell might not be in at dawn but should be by mid-late morning with Middleton pulsing back to 3ft to possibly 4ft through the day as the Mid Coast remains tiny thanks to the southerly swell direction and blocking effects of Kangaroo Island. Conditions will be great with a N/NE tending N/NW breeze, making it an all day affair.

On Friday, a trough will move through around dawn, bringing a S-S/SE change though without much strength across the South Coast while the Mid Coast should see variable winds most of the day.

Now, this trough will be associated with a healthy frontal progression moving in from the south-west of Western Australia this week, though the strength of the system as a whole has been downgraded since last week.

Instead we’re looking at fun, though only moderate levels of mid-period W/SW-SW swell into this Friday afternoon and weekend, with fetch strength mostly falling below gale-force.

The head of the frontal progression looks to generate some initial mid-period W/SW swell through Friday afternoon, while a more favourably aligned fetch of W/SW winds, south of the Bight and in our south-western swell window on Thursday should provide the most size through Saturday. 

The Mid Coast should build to 2ft into Friday afternoon and hold this size into Saturday morning with the South Coast building to 3-4ft later with 4-5ft sets likely on Saturday.

Local winds on Saturday look great for the South Coast and N/NE through the morning with E/NE tending N/NE winds on the Mid Coast ahead of weak, variable sea breezes. Sunday looks similar wind wise as the swell energy starts to ease.

Into next week, as the mid-period energy eases, some longer-range and inconsistent groundswell from the earlier stages of the frontal progression, south of the Indian Ocean is due early next week, though closer-range swell sources may overtake this. More in the next update.