Java, Bali, Lombok, Sumbawa forecast by Craig Brokensha (issued Thu 17th Jul)

Best Days: Every day over the coming period besides Monday morning

This week and weekend (Jul 18 - 20)

A large and powerful S/SW groundswell should be impacting Bali and surrounds today, with a peak expected later this afternoon to 10-12ft at exposed spots.

Through tomorrow and into the weekend a gradual drop in size is expected but this will be softened as a large reinforcing S/SW groundswell fills in through tomorrow afternoon and then also eases Saturday and Sunday. Exposed spots around Bali should ease from 10ft to occasionally 12ft tomorrow morning and then down from 6-8ft+ Saturday morning.

Conditions should be workable across most breaks with a light variable breeze each morning ahead of moderate E/SE trades into the afternoons.

Next Monday onwards (Jul 21 onwards)

Monday morning is still looking to be the low point in activity ahead of an inconsistent pulse of long-range SW groundswell into the afternoon. The source of this swell wasn't very strong or significant and the swell should simply top exposed spots back up to the 6ft+ range into the afternoon before backing off slowly Tuesday.

A secondary similar pulse of slightly more southerly swell is due through Wednesday but to a touch smaller size. Freshening E/SE trades will also limit options to more protected breaks which will be smaller than exposed spots.

Into Wednesday afternoon and Thursday a mix of S/SW groundswells are due, the largest being the least consistent.

The inconsistent S/SW groundswell will be generated by an intense but small polar low firing up south-west of WA later Friday and through the weekend, with this swell possibly showing later Wednesday before peaking Thursday at an inconsistent 6ft to occasionally 8ft.

The more consistent S/SW swell should then be produced by a more northward positioned frontal system pushing up closer towards us and into the central WA coast on Monday. The size from this system will be a bit smaller but more consistent and in the 6ft+ range Thursday.

Longer term a large and long-range SW groundswell is on the cards for the following weekend, but we'll review this Tuesday.

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