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

This week through next week/weekend (Jun 30 – Jul 7)

All locations are expected to see slowly easing levels of SW groundswell into the end of the week, with some small, mid-period S/SE swell across selected locations in Indonesia.

This mid-period energy should make its way to the Maldives on the weekend, peaking Sunday.

Of greater importance is the strong activity firing up through the Indian Ocean from tomorrow through most of next week.

Our initial, high-riding mid-latitude low followed by a frontal system close behind should generate a moderate to large sized mix of SW-S/SW swell for Indonesia next Wednesday/Thursday, with it tending more S'th thanks to a final pulse Friday.

The progression is a good one with an initial fetch of gale to near severe-gale S/SW winds due to be followed by SW gales and then a more distant, polar fetch of gale to severe-gale S/SW winds through Indonesia's southern swell window.

This will produce a pulsey mix of swells that will show later Tuesday, build through Wednesday, hold Thursday and then be followed by a reinforcing S'ly groundswell pulse Friday.

Across western Indonesia the swell should show into Tuesday afternoon and be biggest Wednesday afternoon/Thursday morning before becoming less consistent but still strong Friday.

The Maldives will see the swell from the first low arriving Tuesday, building through the day, but the secondary piggybacking fetch should generate the most size Wednesday.

We then look to the secondary flurry of activity that's due to follow the mid-latitude systems, and that will be a broad, elongates Southern Ocean frontal progression emerging from under South Africa Sunday.

We're expected to see a great fetch of gale to severe-gale W/SW winds projected east, followed up by weaker, scattered fronts through early to mid next week.

What this should produce is a moderate to large, inconsistent SW groundswell for next weekend (peaking Monday the 10th), with the easing trend being slow thanks to the trailing activity. The Maldives should see the swell arriving later next week, peaking Saturday.

At the same time, some healthy SE trade-swell is still on the cards for later next week in the Maldives thanks to an expansive fetch of E/SE-SE winds developing across the Indian Ocean. It looks like the fetch will become super-charged into next weekend, generating a moderate to large increase through the following week but we'll continue to monitor this.

Eastern Indonesia:

Easing inconsistent SW groundswell today, further tomorrow.

Small, weak, mid-period S/SE-S swell for Friday/Saturday/Sunday.

Light, local offshore winds tomorrow morning ahead of freshening SE-S/SE trades, stronger through the weekend. Winds easing a touch Monday with variable early winds, fresh E/SE into the afternoon. Similar through most of the week with afternoon SE trades.

Mod-large mix of SW and S/SW groundswells building later Tuesday but more so Wednesday with a groundswell peaking into the afternoon, easing slightly Thursday. 6-8ft surf developing Wednesday afternoon, easing from a similar size Thursday morning, with a reinforcing S'ly groundswell Friday to 6-8ft, easing Saturday.

Moderate to large, inconsistent SW groundswell building later Sunday (9th), peaking Monday (10th) to 6ft to occasionally 8ft across exposed breaks.

Uluwatu 16-day Forecast Graph/WAMs

Western Indonesia/Mentawais/South Sumatra:

Easing inconsistent SW groundswell tomorrow.

Moderate sized mid-period S/SE swell for Thursday/Friday to 4ft, easing Saturday.

Variable winds tomorrow and through the weekend. Strengthening S/SE-SE winds through next week across southern regions.

Mod-large mix of groundswell and mid-period S/SW-S swell building Tuesday, peaking Wednesday/Thursday, reaching 6ft+ exposed breaks. Moderate to fresh SE-S/SE winds.

Larger S/SW groundswell building Sunday (9th), peaking Monday (10th) to 6ft to occasionally 8ft across exposed breaks.

Mentawai 16-day Forecast Graph/WAMs

Maldives:

Easing S'ly groundswell across the southern atolls tomorrow, smaller into the weekend.

Small-moderate sized SE trade-swell for later Saturday, peaking Sunday to 3ft, easing Monday.

Moderate W/SW winds Friday, tending weaker S-S/SE across the south through Saturday, fresher Sunday. W/SW winds around Male Saturday, shifting S/SW Sunday.

Moderate sized S'ly groundswell pulse building Tuesday across the southern atolls, reaching 4-5ft+, with a secondary larger pulse Wednesday to 5-6ft. Smaller across Male.

Secondary pulse of S'ly groundswell building later Friday (7th), peaking Saturday to 6ft across the southern atolls.

Moderate sized + SE trade-swell building Thursday (6th), peaking through Friday/Saturday (7th/8th) to 4-5ft+ (bigger southern atolls).

Larger SE trade-swell for early the following week mostly likely to 6ft.

Persistent W/SW-S/SW winds across the central atolls most of next week, weaker into Thursday/Friday. Strong S/SE winds across the southern atolls next Monday/Tuesday, easing from Wednesday.