Java, Bali, Lombok, Sumbawa forecast by Craig Brokensha (issued Thursday 25th August)

Best Days: Exposed breaks the coming week or so, Bukit reefs from later next week

This week and next (Aug 26 – Sep 2)

Some new but inconsistent swell has been seen the last couple of days, but winds were a little funky yesterday, straightening out into today.

Today's secondary S/SW groundswell should slowly ease back into tomorrow with 4-6ft sets at magnets early, smaller to 4ft through the day.

A long-period and inconsistent S/SW groundswell is due Saturday, generated by a strong polar low east of Heard Island earlier this week.

The swell hit WA today with good 5-6ft sets, with it expected to offer inconsistent 4-5ft waves at magnets Saturday, easing back slowly Sunday.

Monday will be smaller and around 3-4ft or so, while our acute S'ly groundswell from the mid-latitude low is still on the cards for later Tuesday/Wednesday.

This low will form west-southwest of WA Friday and aim a fetch of S/SE gales towards West Java and the Ments rather than Bali.

We should still see some OK swell filling in though, kicking to 5-6ft Tuesday afternoon, easing from 4-6ft Wednesday morning, further Thursday morning.

Conditions over the coming week should be good with weak E/SE trades, light and variable each morning.

Into the end of next week, a strong but very inconsistent long-range SW groundswell is due, generated by a strong polar low that's fired up under South Africa yesterday (ASCAT right).

This low is very slow moving, almost stalling while generating severe-gale to storm-force W/SW winds. It's currently weakening slightly, leaving a long-range, long-period SW groundswell to head up towards us over the coming days, arriving later Wednesday but not really showing size until Thursday

The swell should build to an inconsistent 5-6ft Thursday afternoon, peaking Friday to 5-6ft+. Expect very very long waits for these sets though.

A secondary frontal progression piggy-backing up over the top of the low should produce a secondary pulse of slightly more consistent SW groundswell for Friday afternoon and Saturday morning to a similar size.

Of much greater importance and as indicated in the last update is the development of a couple of large and powerful S/SW groundswells for the following week.

This will be the result of a strong node of the Long Wave Trough peaking across the Indian Ocean, directing a series of very broad and strong polar fonts high up into the Indian Ocean mid-late next week.

A couple of large S/SW groundswells will be generated, the first for Monday followed by a secondary pulse late week. Size wise we're looking at surf in the 10ft range, but more on this Tuesday.

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