South Australian Forecast by Craig Brokensha (issued Monday September 22nd)

Best Days: Tomorrow morning South Coast, Wednesday morning South Coast, Thursday South Coast, Friday South Coast, Saturday both coasts (Mid afternoon), Sunday South Coast, Monday South Coast

Features of the Forecast (tl;dr)

• Easing surf tomorrow with W/NW tending W/SW-SW winds
• Moderate + sized mix of SW groundswell and mid-period S/SW swell building Wed with a large S/SW groundswell for Thu AM
• W/NW tending W/SW-SW winds late AM Wed
• Fresh W/NW tending NW winds Thu
• Smaller Fri with a moderate sized, reinforcing S/SW swell with strong N/NW tending W/NW winds
• Large mix of mid-period and SW groundswell building Sat, peaking Sun AM
• Light N/NW tending W/NW winds down South Sat, variable tending NW on the Mid 
• Fresher W/NW winds Sun
• Easing swell Mon with strong W/NW tending W/SW winds

Recap

It was a cold, windy weekend of surf with protected spots off the South Coast offering the best waves, chunky Saturday with Sunday coming in a little more settled. The Mid Coast was onshore and poor with nothing to really work with.

This morning we’ve got a shift in winds to the south with some larger S/SW energy filling in down South, but conditions are poor and onshore with cleaner, peaky 1-1.5ft waves inside the gulf.

This week and weekend (Sep 23 - 28)

As touched on last week, we’ve got a very active forecast period ahead, with generally favourable winds for protected locations on the South Coast and large S/SW swells pulses due from mid-week through the weekend.

This will be thanks to an over active Southern Ocean storm track firing up through the coming week in close proximity to the Victorian coastline (under the influence of a strong node of the Long Wave Trough), with the activity due to continue next week but at more of a distance and to the south-west of Western Australia, allowing winds to shift more north-east.

Firstly, looking at tomorrow and our large mid-period S/SW swell for today is expected to start easing and winds look moderate out of the W/NW tending W/SW-SW through the mid-late morning.

Middleton should back off from 3-5ft with the Mid Coast coming in tiny.

Moving into Wednesday, we’ve still got our mix of long-range, inconsistent SW groundswell and mid-period S/SW swell due to build.

There’s been no changes to the long-range energy, with the distant but significant polar low linked to it last week expected to provide infrequent 4ft sets across Middleton (maybe 1-2ft later inside the gulf), while the head of a strengthening polar frontal progression sliding in tomorrow should produce a bit more consistent energy to 4-5ft through the afternoon.

Local conditions look to play out similar to tomorrow with a morning W/NW breeze, shifting W/SW-SW through the late morning/afternoon but without too much strength.

Of greater significance is the surf outlook for Thursday, with a larger S/SW groundswell due to fill in, generated by the polar front moving under the country today through Wednesday. 

A strengthening fetch of W/SW tending SW gales will be steered up and across Tasmania, with the large S’ly energy due to peak through the morning to a strong 6ft, with the southerly angle getting in nicely to the Victor region.

Local winds look great and fresh out of the W/NW tending NW through Thursday, with the Mid coming in bumpy but with no real size owing to the southerly direction.

A slight drop in size is due into the afternoon, smaller Friday, though a secondary, reinforcing S/SW pulse produced by a secondary polar front pushing up on the tail of the original system should maintain 4ft sets across Middleton under strong N/NW tending W/NW winds.

The down time between large pulses won’t be long, with a second strong polar frontal system expected to project up, closer towards us through the end of the week/weekend, bringing a large, powerful SW groundswell for Saturday afternoon/Sunday morning.

The Mid Coast should see a bit more of this swell (2ft sets) as it’ll be generated a touch further west and north, with the South Coast coming in similar to Thursday size wise later Saturday and Sunday morning.

Local winds look great Saturday morning, N/NW tending W/NW down South, with the Mid Coast seeing variable tending weak NW winds. Fresher W/NW winds will favour the South Coast on Sunday, with easing surf and stronger W/NW tending W/SW winds Monday.

As touched on at the start, mid-late next week looks good with more distant W/SW energy but winds out of the north-east. Check back here Wednesday and Friday for updates on this.