Java, Bali, Lombok, Sumbawa forecast by Craig Brokensha (issued Thu 5th Jun)

Best Days: Every day over the coming period

This week and weekend (Jun 5 - 8)

Medium levels of S/SW groundswell should continue across exposed breaks through the end of the week either side of 5ft but fresh to strong E/SE trades will limit the best options to protected spots, where it will be smaller.

There's no real change to the swell due over the weekend with a large but extremely inconsistent SW groundswell due to arrive overnight Friday and peak through the day Saturday.

Exposed spots should see 6ft waves with rare 8ft bombs but the wait between sets will be around 10-15 minutes due to the large distance between the source of the swell (south-east of South Africa and Madagascar) and Indonesia.

A slight drop in swell is due Sunday but not below an inconsistent 6ft at exposed spots as a reinforcing SW groundswell steadies the easing trend. Trade winds should start to back off through Sunday and further into next week with variable winds likely at selected spots each morning from Tuesday onwards.

Next Monday onwards (June 9 onwards)

Monday afternoon's and Tuesday morning's more consistent SW groundswell is still on track, with a tight but intense mid-latitude pushing up through the Central Indian Ocean showing a fetch of 35-50kt confirmed by satellite observations (right).

This system will weaken a touch earlier than expected a couple of days ago and as a result the size has been pinned back slightly.

The swell should arrive later Monday and peak Tuesday morning to an inconsistent 6ft+ across exposed breaks in Bali, smaller towards Sumbawa. A drop is due into the afternoon and further Wednesday with the next pulse of swell due to arrive through Thursday.

From Thursday onwards we'll see a distinct swing in where the swell will be generated from as a strong blocking high over the Western Indian Ocean focusses frontal activity more up through the South-eastern Indian Ocean and through our southern swell window.

A series of vigorous polar fronts will push up along this path generating large pulses of S/SW groundswell from Friday through Sunday with a possible oversized groundswell for Monday the 16th of June. Trades will continue to back off and tend variable into next weekend, but we'll review this all again on Tuesday.

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