Bali and Mentawais forecast​​​​​​ by Craig Brokensha (issued Thursday 6th October)

Best Days: Friday through Sunday morning Bali, later Monday onwards, Ments Friday through Sunday morning, then later Monday through Thursday

This week and next (Oct 7 – 14)

Bali: Easing surf from a good pulse of S/SW groundswell Tuesday is being seen through today. A new inconsistent S/SW groundswell should fill in tomorrow, providing 5-6ft sets across south facing breaks, fading off slowly through the weekend, mixed in with some mid-period SW energy.

This mid-period energy won't have the strength, speed of power compared to normal swells across the islands.

Another mid-period but bigger SW swell is due later Monday and Tuesday across the coast, with it currently being produced by a strong mid-latitude that's pushing north-east above Heard Island.

The strength of this system has been upgraded a little and with this we should see a touch more size to 5-6ft+ across swell magnets when it peaks Tuesday morning, easing off later in the day and slowly through the rest of the week from the S/SW.

Into the following weekend and early the next week, inconsistent amounts of distant S/SW groundswell are due from strong polar fronts pushing along the shelf.

An initial swell for Sunday is due to 4-6ft, with a secondary similar sized pulse for Monday, easing slowly Tuesday.

A slightly larger increase is on the cards for later Wednesday/Thursday from a more northward projecting frontal system, but we'll have another look at this Tuesday.

We're now expected to see fresh to strong E/SE trades kick in from tomorrow afternoon (variable each morning), easing back into Tuesday and becoming variable for the rest of the period.

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

Ments: Today a new inconsistent SW groundswell is due to build this afternoon, peaking tomorrow through the day to 5-6ft across swell magnets. This swell should ease off slowly through Saturday and more pronounced through Sunday.

The consistent S/SW groundswell for later Monday and Tuesday is still on the cards, with a slight upgrade in the expected sized as listed above.

Monday morning will start small and slow, but into the afternoon a kick to 6ft+ is expected by dark, easing from 5-6ft or so Tuesday morning and further into the rest of the week.

The inconsistent S/SW groundswell energy for Sunday/Monday looks to come in around a similar size to Bali, with the secondary larger swell for Wednesday not so much, and continuing in the 6ft range.

Generally light winds are due over the coming period, from the NW at times, favouring south-east facing breaks.

16 day Mentawai forecast graph
16 day Nias forecast graph
16 day South Sumatra forecast graph