Indian Ocean Basin analysis by Craig Brokensha (issued Thursday 29th August)

This week through next (Aug 30 - Sep 6)

The swell has been easing across the region since Tuesday, with some new, inconsistent SW groundswell due into tomorrow afternoon and Saturday morning, though only moderate in size.

We’ve then got out moderate + sized pulse of mid-period S/SW swell due into later Sunday and Monday morning, with the models over-forecasting the size and incorrectly combining swells.

The source wasn’t overly impressive but it should bring a more consistent and slightly bigger increase in size compared to the energy due over the coming two days.

There’s also due to be some inconsistent S’ly groundswell in the mix Monday across select locations, generated by a strong frontal progression currently south-southwest of Western Australia.

We then look to the strong polar low that’s formed west of the Heard Island region, with this generating a fetch of storm-force W/NW winds on the periphery of our southern swell window.

The low will weaken tomorrow while racing off under Australia, limiting the size potential from this system.

We’re now looking at a moderate-large, inconsistent S/SW groundswell that should arrive Wednesday, building to a peak later in the day/overnight and then ease on Thursday.

The models are again incorrectly combining swells so expect less than what the charts are showing.

Following this, weaker storms look to generate smaller, moderate to possibly large pulses of reinforcing swell for later in the week, but more on this Tuesday.

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Over in the Maldives, we’ve got easing levels of mid-period S’ly swell and S/SE trade-swell, with the S’ly energy picking back up a little through tomorrow.

Better levels of S/SE tending SE trade-swell will develop over the weekend and into next week though as a great fetch of E/SE winds developing south-southeast of the region starts migrating east tomorrow.

Unfortunately the fetch will weaken on the weekend resulting in the largest pulse of S/SE energy filling in Sunday/Monday, easing while tending more SE in direction Tuesday, Wednesday and Thursday.

We’ll hopefully see the trades pick back up mid-late next week in our south-eastern swell window, generating some moderate sized SE trade-swell for Friday/Saturday next week, easing thereafter.

S’ly swell wise, a relatively weak frontal system passing the south-east of South Africa looks to generate some small to moderate sized energy for the southern atolls later next week, with nothing further to really follow.

Eastern Indonesia:

Small-moderate sized, inconsistent SW groundswell for tomorrow, 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 with some infrequent S’ly groundswell to a similar size in the mix.

Mod-large S/SW groundswell building Wednesday, reaching 6ft to possibly 8ft across exposed breaks later, easing Thursday from a slightly smaller size.

Smaller, reinforcing S/SW groundswell late week to 6ft.

Moderate S/SE winds tomorrow and over the 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:

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

Moderate sized S’ly swell for Sunday afternoon to 5-6ft across exposed breaks, easing Monday from a similar size.

Moderate + sized S/SW groundswell for later Wednesday and Thursday morning to 4-6ft across exposed breaks.

Moderate sized S’ly swell through next week.

Strengthening S/SE-SE trades across most regions, strongest to the south. Winds easing a touch Sunday/Monday, strong again thereafter until later week.

Mentawai 16-day Forecast Graph/WAMs

Maldives:

New mid-period S’ly swell tomorrow to 4-6ft across the southern atolls, smaller Male.

Moderate + sized S/SE trade-swell building Saturday, peaking Sunday/Monday to 5-6ft across the southern atolls (smaller Male).

Slowly easing swell Tuesday through Thursday while tending more SE in direction.

Building SE trade-swell next Friday, peaking Saturday to 3-5ft.

Fresh S’ly winds across southern locations tomorrow, tending SW across northern and central locations.

Winds tending variable across southern locations on the weekend, weak W-W/NW across norther locations.

Moderate to fresh W-SW winds across central and northern locations early-mid next week, W/NW later week, S’ly at times to the south (early week) and at other times variable.