South Australian forecast by Craig Brokensha (issued Friday January 24th)

Best Days: South Coast tomorrow morning, Sunday and Monday morning ahead of the change

Features of the Forecast (tl;dr)

• Moderate sized mid-period SW swell building tomorrow, peaking later with light N-N/NE winds down South shifting gusty S early PM, local offshore tending SW then S/SE-SE winds on the Mid
• Temporary drop in size Sun AM ahead of a stronger S/SW groundswell into the PM
• Moderate E/NE-NE winds ahead of relatively weak sea breezes Sun
• Easing S/SW groundswell Monday with strengthening N-N/NW winds, tending W/NW late AM ahead of a strong S/SW change
• Poor S winds Tue with a localised windswell
• Moderate sized S/SW swell Wed with strong S/SE winds

Recap

The Mid persisted in the 1ft+ range yesterday morning before finally fading into the afternoon with the South Coast offering lumpy fun waves to 2ft+ under a morning E-E/NE breeze.

Today the Mid Coast is tiny and to 0.5-1ft while the South Coast is showing some decent swell but with a moderate to fresh S’ly wind.

This weekend and next week (Jan 25 - 31)

The weekend ahead is mixed with tomorrow morning likely to offer the cleanest conditions down South, while Sunday will be less favourable but with more size and power.

This will be thanks to an initial mid-period SW swell building through tomorrow afternoon, being followed by a secondary stronger pulse of S/SW groundswell into Sunday afternoon, with the morning falling just between pulses.

The source of this first swell was a healthy frontal system pushing in towards us, from the Heard Island region with fetches of strong to gale-force W-W/NW winds, weakening slightly on approach.

Middleton should build from 2ft in the morning tomorrow to 3-4ft later afternoon while the Mid Coast may see 1ft to occasionally 1.5ft sets late in the day.

A morning N-N/NE breeze should create decent conditions down South ahead of trough and S’ly change early afternoon, with offshore winds on the Mid ahead of sea breezes, tending back S/SE-SE into the evening.

The swell is due to ease temporarily into Sunday morning ahead of the next increase in S/SW groundswell through the afternoon, generated by our secondary frontal system moving in quickly on the tail of the first.

This secondary system will again generate a fetch of strong to gale-force winds on top of an active sea state, closer in proximity to us but later in our swell window and this should produce a slightly stronger pulse of groundswell to 4ft across Middleton Sunday afternoon (smaller 3ft in the morning) with 1ft to occasionally 1.5ft sets persisting across the Mid Coast.

As touched on above, local winds won’t be as favourable with a morning E/NE-NE breeze down South, E/SE on the Mid though with relatively weak sea breezes across both regions.

Monday morning looks great for the South Coast as the swell eases with a strengthening N tending N/NW breeze that will shift W/NW by later morning ahead of a strong S/SW change. With this in mind, earlier will be better than late.  

This change will be linked to a deepening low to our south early next week, but the models have downgraded the swell potential from this system, with a fetch of W/SW gales only forming late in our swell window.

A moderate sized pulse of S/SW swell is due from this system on Wednesday but high pressure following the low will bring poor, strong S/SE winds that will create terrible conditions down South. The Mid will be cleaner but offer no size thanks to the southerly swell direction.

The end of the week looks no better at this stage so make the most of the weekend and Monday morning. Have a great weekend!