Indian Ocean Basin analysis by Craig Brokensha (issued Tuesday 27th August)

This week through next (Aug 28 - Sep 6)

Our large S/SW groundswell has filled in today and we’ve seen the south-southwest winds spoil conditions across exposed locations this afternoon with the peak in size.

We’ll see the swell ease back through tomorrow, further Wednesday with some reinforcing, long-range SW groundswell from an off axis but strong low that formed off Madagascar late last week.

This low was mainly aimed north towards the Maldives, with some moderate sized but inconsistent swell spreading out radially from it for Friday, peaking into the afternoon and Saturday morning.

Into later Sunday and more so Monday morning, a moderate + sized pulse of mid-period S/SW swell is due, generated by a small low that will project towards eastern Indonesia over the coming days.

The models are over-forecasting the size and incorrectly combining swells, so expect less size than what’s currently shown.

We’ve then got an inconsistent, but strong long-period S/SW groundswell on the cards for mid-late next week with a strong polar low firing up west of the Heard Island region Thursday, generating a great fetch of storm-force W/NW winds, weakening while pushing further east-northeast and under Australia.

The swell won’t come in as big as it could thanks to the system racing ahead of itself a little, with large surf due Wednesday afternoon and Thursday morning.

We may see a secondary, slightly smaller pulse of southerly groundswell for next weekend but we’ll cover this in the next update.

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Over in the Maldives, the weekend’s S/SE trade-swell is due to ease over the coming days thanks to the fetch of swell generating trades weakening a little.

We’ll see the trades pick back up and slowly shift more east through this week and weekend, resulting in building levels of S/SE trade swell later this week and into the weekend, easing slowly next week while tending more SE in direction.

Of greater significance across the southern atolls is a larger S’ly groundswell due into this afternoon and tomorrow morning, generated by a significant low that formed off Madagascar late last week.

This swell will ease through the rest of the week as the trade-swell takes dominance.

Winds look to become a bit of an issue later week, strengthening from the S/SE across southern locations, weaker into next week.

Eastern Indonesia:

Large, easing S/SW groundswell tomorrow from 8ft across exposed breaks.

Small-moderate sized, inconsistent SW groundswell for Friday, building to 4-5ft, easing from 3-5ft Saturday morning

Moderate + sized, mid-period S/SW swell for later Sunday, peaking Monday morning to 5-6ft across exposed breaks.

Large S/SW groundswell building Wednesday, reaching 8ft across exposed breaks, easing Thursday from a similar size.

Moderate S/SE winds over the coming days and weekend, variable each morning, with moderate to fresh E/SE-SE trades for next week.

Uluwatu 16-day Forecast Graph/WAMs

Western Indonesia/Mentawais/South Sumatra:

Large, easing S/SW groundswell over the coming days.

Inconsistent, moderate + sized SW groundswell Thursday to 5-6ft across exposed breaks.

Moderate sized S’ly swell for Sunday afternoon to 4-6ft across exposed breaks, easing Monday.

Moderate to large S/SW groundswell for later Wednesday and Thursday morning to 6ft across exposed breaks.

Moderate sized S’ly swell through next week.

Strengthening S/SE-SE trades over the coming days, lighter to the north tomorrow. Winds easing a touch but remaining fresh early next week.

Mentawai 16-day Forecast Graph/WAMs

Maldives:

Easing S/SE swell over the coming days, before building again later week, peaking on the weekend to 5-6ft across exposed breaks (smaller Male).

Swell slowly easing and tweaking SE next week.

Larger S’ly groundswell for later today and tomorrow morning to 6-8ft across the southern atolls.

E/SE-SE winds across southern locations tomorrow (W/SW-SW to the north), strengthening from the S/SE Friday with S/SW winds to the north.

Easing winds into the weekend, E/SE to the south and W/NW to the north.