With the transition of seasons into autumn, the Southern Ocean has already fired off a couple of large swells for the southern states.

This activity is continuing through this week and weekend, but as we head into early next week, a strong node of the Long Wave Trough responsible for storms will move east of Tasmania, across the entrance to the southern Tasman Sea and stall.

The prime swell window for Fiji is from deep in the Southern Ocean under Tasmania up through the Tasman Sea, and this is the exact path storms take when the Long Wave Trough stalls east of Tasmania.

This setup is currently forecast to develop early next week and with that a vigorous polar low will develop south-west of Tasmania Monday morning, projecting an elongated fetch of severe-gale to storm-force SW winds ideally up past Tasmania and through the entrance to the southern Tasman Sea.

The storm will travel at a similar speed and in a similar direction to the swell its producing resulting in a captured fetch scenario, enhancing the size and power of the swell.

A large long-period S/SW groundswell will result, impacting the East Coast later Wednesday and Thursday next week with large 6-8ft sets due across south facing beaches at its peak.

Long-period fore-runners around 22s are due to impact Fiji later Friday, with the bulk of the groundswell filling in Saturday afternoon/evening and reaching 10ft+ by dark across Cloudbreak.

A peak is likely overnight/early dawn Sunday week, with large 10-12ft sets, easing back slowly through the day.

Winds this far out are a little hard to pin down, but it looks like we'll see light variable winds both Saturday and Sunday mornings, possibly onshore from the SW Saturday afternoon. This is surely due to change though, but the swell is looking rock solid.