Nias, Mentawai, South Sumatra forecast by Craig Brokensha (issued Thursday 17th September)

Best Days: Protected spots from Saturday afternoon through all of next week

This week and next week (Sep 18 - 24)

Easing amounts of swell and poor winds continuing across the region today, with tomorrow likely to be a lay day as the swell bottoms out.

Into the weekend a strong but inconsistent SW groundswell is due to build through Saturday and peak Sunday morning, generated below South Africa late last week.

Exposed breaks should build to an infrequent 6ft+ later Saturday and then ease from 6ft to occasionally 8ft Sunday morning but with fresh S/SE winds.

A further drop is then due through Monday ahead of a large new S/SW groundswell on Tuesday.

This groundswell is currently being generated through the southern Indian Ocean to the south-west of WA, with a broad fetch of severe-gale W/SW winds setting in motion an active sea state for a stronger fetch of storm-force SW winds to move over, projecting north-east through our southern swell window.

The swell is due to kick overnight Monday and peak through the day Tuesday morning to a solid 6-8ft+ across exposed breaks, easing gradually through the rest of the week.

Fresh S/SE winds are due to ease through Tuesday, lighter into Wednesday before picking up again into Thursday.

Longer term there's nothing too major on the cards for the end of the month beside moderate pulses of S/SW swell with persistent S/SE winds, but we'll have another look at this again on Tuesday.

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