Java, Bali, Lombok, Sumbawa forecast by Craig Brokensha (issued 14th April)

Best Days: Swell magnets until Friday, your favourite reef from then onwards

This week and weekend (Apr 15 - 19)

The surf is back to the small range this week with exposed breaks and swell magnets the go with light variable and offshore winds each morning ahead of weak afternoon E/SE trades.

From Friday we'll see the first of three large groundswell pulses impacting the region, generated by a series of vigorous polar frontal systems firing up in the Indian Ocean under the influence of a strong node of the Long Wave Trough.

The first system developed south-east of South Africa on Saturday and pushed east towards Western Australia while generating a fetch of severe-gale to storm-force W/SW winds.

An inconsistent and long-period S/SW groundswell has been produced by this low, with it expected to build through Friday and reach 5-6ft+ at exposed breaks into the evening. Saturday morning should offer similar sized waves ahead of a drop through the afternoon.

A secondary more southerly but slightly more consistent S/SW groundswell is then due to Sunday, generated by secondary polar low firing up south-west of WA this morning, generating a pre-frontal fetch of severe-gale W/NW winds, followed closely by a better aligned fetch of severe-gale W/SW winds.

Exposed breaks are due to offer larger 6-8ft waves Sunday morning before easing into the afternoon and further Monday.

Conditions will continue to be favourable and clean each morning with light variable winds ahead of afternoon sea breezes.

Next Monday onwards (Apr 20 onwards)

While Sunday's swell will back away into Monday from the 5-6ft range, out final pulse of groundswell is due Tuesday.

This last swell pulse will be very southerly in nature, generated right on the edge of our swell window to the south-west of WA by a strengthening and intense polar low.

A fetch of storm to near hurricane-force W/SW winds will be aimed mainly towards Southern Australia before the low pushes east and into the shadow of Australia, with an inconsistent but strong S'ly groundswell pushing up towards us and arriving later Monday, peaking early Tuesday.

Exposed breaks are expected to offer inconsistent 6ft sets before easing through the afternoon and then down through the rest of the week.

Longer term there's nothing too major with moderate amounts of background swell energy, but we'll look at this closer on Thursday.

16 day Bali Forecast Graph
16 day East Java Forecast Graph
16 day Sumbawa Forecast Graph