South Australian Forecast (issued Wednesday 7th May)

Best Days: Thursday, Friday for keen surfers, Saturday arvo on the Mid, Sunday, Monday, Tuesday

Recap

A strong new S/SW groundswell built through yesterday, and while starting slow early on the South Coast, build to an easy 4-5ft around the Victor and Middleton stretch. Winds were OK early and from the E/NE but fresh SE sea breezes spoilt conditions into the afternoon. The Mid Coast was clean all day but tiny.

Today the swell is easing from a slightly smaller 3-4ft at Middleton, with bigger sets out at Waits under more favourable N/NE winds, creating good conditions. The Mid Coast was clean as well but near flat with a tiny trickle of swell.

This week and weekend (May 7 - 11)

The forecast for the end of the week is quite simple. Today's swell will continue to fade, and a reinforcing SW groundswell due tomorrow won't really halt the easing trend with the surf expected to bottom out Friday afternoon and early Saturday.

Winds tomorrow will remain favourable for the South Coast and offshore from the N/NE, while Friday will see strong but easing N'ly tending N/NW winds, creating tricky conditions for paddlers.

Into the weekend a good new W/SW groundswell is due across both the Mid and South Coasts Saturday, generated by a mid-latitude front dipping south-east from WA and aiming a broad fetch of strong to gale-force W/SW winds through the Bight.

This should kick up 2ft+ of swell across the Mid into the afternoon while the South Coast should build to 2ft at Middleton and 3ft+ at Waits later in the day. Unfortunately winds will swing onshore from the SW after a morning NW'ly across the South Coast, but in saying this, the Mid Coast should still be worth a look into the afternoon.

Sunday looks like the best day to surf with an easing swell and light local offshores across both coasts that should tend variable into the afternoon.

Monday onwards (May 12 onwards)

Heading into Monday, a strong and powerful long-range SW groundswell is due to fill in and peak into the afternoon.

The source of this swell is a vigorous polar frontal progression in our far swell window over near Heard Island.

Yesterday and this morning, an initial polar low generated a fetch of 35-50kt winds, setting in motion a large and active sea state as well as an initial small long-period swell for later Sunday. Cape du Couedic will pick this up during the morning but no major size is due and any increase will be seen through the afternoon.

A secondary vigorous polar low will quickly race in over the top of the active sea state in the Southern Indian Ocean, generating an additional fetch of 35-45kt+ W/SW winds while projecting towards WA.

This should set in motion a large and powerful but long-range SW groundswell that should arrive early Monday morning and build strongly into the afternoon, reaching a really inconsistent but strong 4-5ft at Middleton and 6ft at Waits, while the Mid should see 2ft+ sets on the incoming tide.

A peak in size is due during the evening, but Tuesday will still provide solid waves as a flurry of secondary frontal activity being pushed towards WA and then deflected back down towards the poles continues to send swell our way.

Conditions on Monday look excellent with light N/NE tending variable winds while Tuesday should see fresh N/NE winds persisting all day. Longer term a medium sized SW groundswell is on the cards for Friday but we'll review this in the next update.