Java, Bali, Lombok, Sumbawa forecast by Craig Brokensha (issued Tue 15th Jul)

Best Days: Thursday through Sunday across all breaks, Monday onwards out of the trades

This week and weekend (Jul 16 - 20)

The swell seen late last week backed off over the weekend, but a reinforcing S/SW groundswell should of softened this drop through this morning a touch. A further drop in size is due through this afternoon ahead of a low point tomorrow morning. It's probably worth giving the surf a miss and focussing on a couple of large and powerful S/SW groundswells through the end of the week.

These groundswells were generated late last week and through the weekend by a couple of vigorous polar fronts pushing up from south-east of South Africa, over the Heard Island region under the influence of the Long Wave Trough.

A late kick in size may be seen tomorrow across the region, but the swell will fill in with gusto on Thursday, building to a large 10-12ft at exposed breaks around Bali during the day.

A peak is likely through the afternoon ahead of a slow drop through Friday and Saturday, but a reinforcing S/SW groundswell will slow this easing trend, generated by a polar front pushing up into the South West corner of WA yesterday and early this morning.

Exposed spots should ease slowly from 10ft+ Friday morning ahead of a more noticeable drop from 6-8ft+ Saturday morning and then 5-6ft Sunday.

Winds over the coming days will really back off and be generally variable each morning ahead of light to moderate E/SE trades into the afternoon. This should open up plenty of options across more exposed south-east facing breaks which will also be getting a lot of size due to the extra south in the swell direction.

Into Sunday and more so Monday though they're expected to kick up again and become quite strong through Tuesday and Wednesday next week.

Next Monday onwards (Jul 21 onwards)

Monday morning will become a low point in size, but into the afternoon a couple of long-range and inconsistent SW groundswells are due. The source of these swells will be a couple of small mid-latitude frontal systems tracking on a less than favourable east-southeast track through the Southern Indian Ocean, but the strength of each system will help generate some decent size.

Both swells are expected to arrive through Monday and build to an inconsistent 6ft+ across exposed spots in Bali through the afternoon before easing back from 5-6ft or so Tuesday morning.

Longer term we're looking at some better and larger S/SW groundswell into the end of the weekend with the possibility of an even stronger event Wednesday, but we'll review this Thursday.

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