Indian Ocean Basin analysis by Craig Brokensha (issued Tuesday 26th March)

This week through next (Mar 27 - Apr 5)

Small surf is breaking across the region, with no major change due to the outlook for this week. 

We may see a small pulse of S/SW swell into later Wednesday but more so Thursday generated by a late forming low to the south-west of Western Australia. This showed to 3-4ft across the Margaret River region with it not expected to top 3ft in Indonesia from Bali, west to Java.

Of greater importance is the large SW groundswell due into Sunday and more so Monday next week, with the strong, northward projecting frontal progression linked to it, currently pushing up into the Indian Ocean.

A polar fetch of W/SW gales has now transitioned into a weaker, northward projecting fetch of strong to gale-force S/SW winds, with the front due to weaken tomorrow, followed by weaker fetches of W/SW winds.

What we can expect size wise is a large SW groundswell, followed by reinforcing mid-period S/SW energy.

A slow increase in size is due Sunday, pulsing strongly later in the day, peaking overnight though holding Monday morning before easing slowly into Tuesday and Wednesday.

Following this, there’s nothing major due with the Indian Ocean falling quiet, so make the most of the swell due from Sunday.

Over to the Maldives and stronger levels of SE trade-swell linked to Tropical Cyclone 18s (eventually named Neville) are on the build, generated as the TC squeezed a strong high pressure system sitting in the Indian Ocean.

This swell should peak through tomorrow morning with the period putting it up into the groundswell category, then easing slowly into the end of the week.

Come the weekend, the large S’ly groundswell from the northward projecting frontal system will move in, with it being the largest swell of the season so far for the southern atolls.

The swell should build through Saturday and become large later, holding Sunday morning before easing off slowly into next week.

Eastern Indonesia:

Possible small S’ly groundswell signal late Wednesday, peaking Thursday morning for Bali and locations west.

Large mix of SW swells arriving late Saturday week, building slowly Sunday, reaching 6ft to occasionally 8ft into the evening, easing Monday from a similar size. Swell fading further through next week.

Weak E/SE-S/SE trades, variable offshore each morning.

Uluwatu 16-day Forecast Graph/WAMs

Western Indonesia/Mentawais/South Sumatra:

Large mix of S/SW swells building later Saturday, peaking Sunday afternoon to 6-8ft across the magnets, easing from a similar size Monday morning, smaller into the rest of the week.

Variable winds this period, tending N/NW tomorrow afternoon, and S/SE from the weekend across southern locations.

Mentawai 16-day Forecast Graph/WAMs

Maldives:

Stronger SE swell building slowly today, peaking tomorrow morning to 4-5ft across exposed breaks, easing slowly into the end of the week.

Large S’ly groundswell building Saturday, reaching 6ft to occasionally 8ft on the southern atolls late, easing Sunday from a similar size, further next week.

Variable winds today, tending light E/NE on Thursday, E’ly Friday. Light to moderate E/SE winds Saturday, weaker E/NE on Sunday, NE Monday.