Indian Ocean Basin analysis by Craig Brokensha (issued Tuesday 4th February)

This week through next (Feb 5 - 14)

The Indian Ocean basin is currently awash with tropical cyclones thanks to an active phase of the MJO moving through the region.

We’ve currently got Tropical Cyclone Taliah sitting south of Java, pumping gale to severe-gale W’ly winds through our western swell window but while moving away from us which isn’t ideal.

Regardless, a moderate + sized, mid-period W/SW swell is due from this source tomorrow, peaking through the day before easing off slowly into the end of the week and weekend as it tracks away to the west-southwest.

With the acute westerly direction and local offshore winds there’ll be some funky options at spots exposed to the swell.

Otherwise we look to the long-range, inconsistent SW groundswell due into Thursday afternoon and Friday, mixed in with some more consistent mid-period energy.

The source of both these swells was a strong low that formed south of South Africa early last week, pushing east while broadening and weakening, resulting in the formation of a longer-range groundswell and closer-range mid-period swell.

While kicking Thursday afternoon a peak is likely Friday morning, then easing into the afternoon and smaller through the weekend.

Into later Saturday but more so Sunday, a very acute, long-period S/SW groundswell is expected across selected spots, generated by a strong low forming late in our swell window, south-west of Western Australia. This low actually came about as the remnants of Tropical Cyclone Elvis which was south-east of Madagascar, tracked south-east and was absorbed into the westerly storm track.

A great fetch of severe-gale to storm-force winds should produce a noticeable increase in size late Saturday but more so Sunday, before easing rapidly Monday. Otherwise there’s nothing of significance to work with next week.

Monsoonal W’ly winds will also kick up again from this weekend, strong W/NW-W/SW, persisting through early next week weakening slowly from Wednesday but more so later week.

In the Mentawais, persistent, strong W’ly winds out in the Indian Ocean will bring moderate levels of W/SW swell across the southern and central regions this week, fading into the weekend before likely picking up again through next week.

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Maldives: Later today we should see some good S’ly groundswell arriving across the southern atolls, peaking through tomorrow but holding well into Thursday morning.

This was generated by the strong polar low that formed south of South Africa and with this we should see moderate sized sets.

We then look to some more favourable, mid-period SE swell emanating off all the cyclone activity in the Indian Ocean at the moment.

A good fetch of strong SE winds on the southern flank of Tropical Cyclone Vince should produce a decent mid-period pulse for later Thursday but more so Friday.

This will then be backed up by a secondary pulse of SE groundswell later Sunday but more so Monday, generated off a tight but stronger fetch surrounding Tropical Cyclone Taliah.

The size looks possibly a touch smaller but with more power, easing slowly next week while tending more S/SE in direction as Taliah tracks further west.

Local winds will be generally best across the southern and central atolls, more onshore out of the NE to the north.

Eastern Indonesia:

Moderate + sized W/SW-SW cyclone swell tomorrow to 6ft+ across exposed breaks, easing slowly into the end of the week and weekend.

Moderate to large sized mix of SW groundswell and mid-period S/SW swell building to 6ft later Thursday, easing from 6ft+ Friday morning, smaller Saturday.

Moderate sized, short-lived spike of S/SW groundswell late Saturday but more so Sunday morning to 4-6ft, easing thereafter.

Light, variable locally offshore winds, variable into the afternoons. Winds strengthening from the W/NW-W/SW on the weekend, easing from mid-next week.

Uluwatu 16-day Forecast Graph/WAMs

Western Indonesia/Mentawais/South Sumatra:

Moderate sized W’ly swell this week, easing slowly into the end of the week and next weekend. Possibly picking up mid-late next week again.

Moderate to large sized S/SW groundswell building to 6ft+ Thursday afternoon, easing Friday.

Variable winds, tending W/NW-NW across far southern locations at times.

Mentawai 16-day Forecast Graph/WAMs

Maldives:

Moderate sized S’ly groundswell building later today, peaking tomorrow to 4ft+ across the southern atolls, easing slowly Thursday.

Mid-period SE swell building later Thursday, peaking Friday to 4ft+, easing slowly Saturday.

Less consistent SE groundswell for later Sunday but more so Monday to an inconsistent 3-4ft.

Light N-N/NE winds, freshening from the NE across northern and central locations over the coming days (N/NW to the south). Winds tending more E/NE across northern and central locations later week and then stronger NE on the weekend.