Nias, Mentawai, South Sumatra forecast by Craig Brokensha (issued Tuesday 16th Jun)

Best Days: Thursday onwards

This week and next week (Jun 17 – Jun 26)

A low point in swell activity was seen this morning across the region, but a slight kick in inconsistent background S/SW groundswell is due this afternoon and through tomorrow but only to 3-4ft+ across exposed breaks.

Come Thursday our strong S/SW groundswell is right on track with the swell due to build through the day and reach a good and large 6-8ft+ across exposed spots through the afternoon, easing back from 6-8ft Friday morning and further into the weekend.

Conditions should be generally favourable tomorrow but a weak S/SE trade is due to develop through Thursday and Friday, lingering through the weekend and into early next week. South Sumatra is expected to see stronger trades from the E/SE-SE.

Into next week there's nothing significant on the cards, with an acute and small S'ly groundswell due for Eastern Indonesia, not making much of an impact across our region as the polar low producing it will form too far east and late in our swell window.

There should still be a signal of S'ly swell Monday from this source, coming in at a very infrequent 3-5ft before easing into the afternoon and further Tuesday.

Longer term we're likely to see some large S/SW groundswell at the end of the month, as a strong node of the Long Wave Trough moves through the Indian Ocean early next week.

A series of broad and vigorous polar fronts are due to fire up, with a couple of large S/SW groundswell pulses on the cards to end the month. We'll have a closer look at this on Thursday though.

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