South Australian Surf Forecast by Craig Brokensha (issued Monday December 18th)

Best Days: Mid Coast tomorrow afternoon and Wednesday morning, South Coast Saturday morning

Features of the Forecast (tl;dr)

• Moderate + sized W/SW-SW groundswell building tomorrow, peaking in the PM with fresh to strong S/SE winds
• Easing groundswell Wed with gusty SE tending strong S/SE winds
• Poor S/SE windswell Thu with gusty SE tending S/SE winds
• Easing S/SE windswell Fri with light S/SE winds, strengthening
• Small-mod sized mid-period SW swell Sat with variable W/NW tending fresh SW winds
• Strong S/SE winds Sun with a poor windswell

Recap

Saturday was small and clean for the keen on the South Coast, tiny and choppy on the Mid Coast, but yesterday provided good surf across both regions. The Mid Coast was full but clean and to 1-1.5ft with the arrival of a new W/SW-SW swell, a much better 3-4ft and clean on the South Coast with options all over.

This morning, the surf was smaller but nice and clean early down South though a trough has brought an early S'ly change so I hope you got in over the past couple of days!

Full, fun waves yesterday morning in the gulf (better down South)

This week and weekend (Dec 19 - 24)

Following this morning's S'ly change, we're now going to be set in an embedded pattern of mid-latitude located highs broken up by troughs.

This will bring cooler weather and persistent poor conditions for the South Coast, while the Southern Ocean storm track will be active but positioned too far south to be favourable for the Mid Coast which will have cleaner conditions.

That's why the coming moderate + sized W/SW-SW groundswell for tomorrow and Wednesday will be worth trying to capitalise on in the gulf.

There's been no change to the expected size and timing of the swell, with it generated by a strong polar low that fired up around the Heard Island region last Thursday (right). The low projected east-northeast while generating severe-gale to storm-force winds in our far swell window, weakening while pushing under the country during the weekend.

The swell hit WA hard late yesterday and overnight with it due to build strongly through tomorrow ahead of a peak in the afternoon. The Mid Coast should build to 1-2ft and ease from 1ft to possibly 2ft Wednesday morning with the South Coast building to 4-5ft+ tomorrow, easing from 4ft Wednesday.

Winds now look more favourable for the Mid Coast tomorrow, though still less than perfect with strong S/SE breeze adding lots of bumps and small chops at most breaks. The South Coast will be poor and a mess.

Winds will swing to the SE as the swell eases on Wednesday creating great conditions, bumpy into the afternoon with stronger S/SE breezes.

The rest of the week remains void of any major groundswell with localised S/SE windswell dominating the South Coast under gusty SE tending S/SE winds Thursday, lighter and more variable on Friday morning.

With the variable winds Friday morning we should see conditions improve but there'll only be weak, junky levels of easing S/SE windswell from 3ft max.

A small-moderate sized background SW swell is due Saturday morning, generated by a weak polar front that's currently east of the Heard Island region. The front will be slow moving but wind speeds below gale-force with a kick to 2-3ft due across Middleton down South, tiny on the Mid Coast.

We may see more variable winds on Saturday morning, tending W/NW locally around Victor, freshening from the SW through the day as the next trough moves in.

This window looks to be worth making the most of as we'll then see strong S/SE winds kick back in again on Sunday, slowly shifting more SE Tuesday and then possibly back E/NE-NE Wednesday week as the next high slides east under the country.

Swell wise, small background levels of mid-period swell should persist next week but we'll have a closer look at this on Wednesday.