Indian Ocean Basin analysis by Craig Brokensha (issued Tuesday 22nd April)

This week through next (Apr 23 - May 2)

The coming period revolves mainly around the SW groundswell into tomorrow and Thursday, with it expected to bring the most size ahead of a slower run into the start of May.

As touched on through last week, the source was a strong but distant low that formed south of South Africa, piggybacked by a secondary frontal system on top of the active sea state as the progression moved slowly east.

The activity as a whole weakened from about the Heard Island region, leaving inconsistent but strong levels of SW groundswell to spread up and into us, with an arrival set for this afternoon/evening.

The bulk of the swell is due tomorrow though and should build steadily all day, peaking later before easing slowly into Thursday and Friday.

Local winds look variable offshore in the mornings ahead of weak sea breezes over the coming days before E/SE-SE trades kick in later Thursday but more so Friday, weakening a little Sunday/Monday before strengthening into the rest of next week.

The only other notable swell is for the weekend and the models are over-cooking the size, combining a long–period swell from a healthy polar low with existing mid-period energy.

In saying that we should still see a decent increase in size through Saturday afternoon, generated by the polar low in question, with a good but slim fetch of severe-gale W/SW winds generated just east of the Heard Island region Sunday evening.

The swell looks moderate + in size, likely peaking later in the day Saturday before slowly easing into Sunday.

Also in the mix will be some moderate sized mid-period S'ly swell spawning off a low forming south-west of WA over the coming days. This looks to arrive later Saturday and into Sunday morning.

Otherwise the Indian Ocean goes quiet so make the most of the coming swell.

In the Mentawais the weekend’s N/NW-NW winds are now abating though lingering out of the NW, with more variable breezes due from about Friday.

Swell wise the increase for the coming days will be best, with the weekend’s swell coming in a little south and too late in our swell window to produce any major size.

----------------------------------------------

Maldives:

Over in the Maldives we’ve got a fun pulse of SE trade-swell in the water, mixed in with the large S/SW groundswell across the southern atolls.

Both these sources are due to ease over the coming days before we see a renewal of S/SE trade-swell energy into the second half of the weekend and more so next week.

The source is a healthy fetch of SE trades that have developed south of us, with a couple of intensifications in the fetch extending west of Western Australia due to produce some stronger mid-period swell energy Tuesday afternoon and Wednesday morning.

It looks moderate in size before easing into the end of the week.

Southern atoll wise, we should see some fun S/SW swell energy into the end of next week generated by a low to the south of South Africa this afternoon and tomorrow, with moderate sized sets likely.

Local winds look to be fresh from the W-W/NW this week and weekend, possibly easing a little next week but we’ll review this Thursday.

Eastern Indonesia:

Inconsistent, long-range but moderate + sized SW groundswell building tomorrow, reaching 6ft+ later if not Thursday morning, then slowly easing.

Mix of moderate + sized, inconsistent S/SW swells building Saturday, reaching 4-6ft across exposed breaks, easing Sunday.

Variable tending locally offshore winds ahead of weak sea breezes over the coming days. Weak E/SE-SE trades kicking in late Thursday but more so Friday, stronger next week (variable offshore each morning).

Uluwatu 16-day Forecast Graph/WAMs

Western Indonesia/Mentawais/South Sumatra:

Inconsistent, long-range but moderate + sized SW groundswell for tomorrow, reaching 6ft+ across exposed breaks, easing Thursday.

Small-moderate mix of S’ly swells building slowly Saturday, peaking Sunday to 4-5ft across exposed breaks, easing thereafter,

Lingering winds from the north-western quadrant, more variable from Friday.

Mentawai 16-day Forecast Graph/WAMs

Maldives:

Easing mix of S/SW groundswell and SE trade-swell over the coming days.

Building S/SE trade-swell Sunday to 3ft+, easing slowly Monday.

Slightly stronger S/SE swell for Wednesday to 4ft, easing into the end of the week.

Moderate sized S/SW swell for later Monday, peaking Tuesday to 4ft across the southern atolls.

Secondary pulse of S/SW swell later week to 4ft across the southern atolls.

Fresh W-W/NW winds this week and weekend, easing next week.