Nias, Mentawai, South Sumatra forecast by Craig Brokensha (issued Tuesday 6th October)

Best Days: Every day over the coming period

This week and next week (Oct 7 - 16)

Our recent large S/SW groundswell is currently on the ease, plagued by fresh S/SE winds.

We've got two final pulses of more southerly S/SW swell into tomorrow afternoon and Thursday from a series of strong frontal systems projecting up and into Western Australia over the weekend and yesterday.

Exposed breaks should kick back to 6-8ft tomorrow afternoon and hold 6ft to occasionally 8ft Thursday before easing back into Friday and the weekend.

S/SE winds will persist tomorrow but ease from Thursday and become lighter and more variable from Friday and more so Saturday.

A couple of inconsistent but fun S/SW and SW groundswell pulses are due into Sunday and then later Monday/Tuesday, the second being a touch smaller but more consistent and from a better direction.

The S/SW pulse is currently being generated by a vigorous but small fetch of severe-gale to sub-storm-force S/SW winds in the Heard Island region, projecting north-east towards Bali.

This should then be followed by a weaker but better positioned system developing east-southeast of Madagascar.

The first pulse for Sunday afternoon should kick to an inconsistent 4-6ft across exposed south facing breaks, easing back into Monday morning, with the secondary kick from the SW peaking Tuesday to 4-5ft.

From here on the swell is then expected to ease ahead of a strong long-period and inconsistent SW groundswell Friday.

This is expected to be produced by a broad, vigorous and slow moving frontal passage firing up under South Africa later this week, aiming a fetch of severe-gale W/SW winds through our south-western swell window.

The swell from this system should peak through Friday to a strong 6-8ft+ across exposed breaks, but we'll have greater confidence on this Thursday.

16 day Mentawai forecast graph
16 day Nias forecast graph
16 day South Sumatra forecast graph