Indian Ocean Basin analysis by Craig Brokensha (issued Tuesday 19th November)

This week through next (Nov 20 - 29)

Moderate levels of S/SW groundswell are breaking across the region this morning and we’ll see this ease into tomorrow as a long-range, inconsistent SW groundswell arrives.

The source was a distant but strong storm and we should see it building slowly tomorrow afternoon ahead of a peak Thursday morning, tailing off thereafter.

Otherwise the period consists of small-moderate pulses of mid-period S/SW swell from an active westerly storm track across the Roaring 40’s. While not overly strong the activity looks persistent and this should produce fun pulses of swell, the first for Sunday afternoon, easing Monday with a secondary similar, if not slightly smaller sized pulse for Tuesday, peaking into the afternoon before easing Wednesday.

Later in the week a small depression forming on the western side of a high off the Western Australian coast could generate some new mid-period S’ly swell Friday, but of greater significance is a stronger low firing up behind this. At this early stage we could see a moderate + sized S/SW groundswell for the following weekend, but we’ll have a closer look at this on Thursday.

In the Mentawais, expect generally smaller surf than eastern Indonesia, (besides tomorrow's/Thursday's groundswell) and a deepening tropical depression to the west of Sumatra looks to bring strengthening W/NW-NW winds from this weekend (SW late week) along with moderate +  levels of mid-period W/NW swell.

Depending on where the axis of the low forms, we may see variable winds next week, or fresh N-NW breezes. Check back Thursday.

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Maldives: In the Maldives, S’ly swell energy will be most dominant across the region for the coming days, showing best across the southern atolls, while the deepening tropical depression off Sumatra should bring strengthening trades and building swell from the S/SE-SE from the weekend.

This swell will mature nicely into next week, and depending on how deep the tropical depression gets, we could see stronger levels of SE energy later next week and into the following weekend. Winds will strengthen at the same time out of the NW-W/NW into next week, feeding into the north-western flank of the tropical disturbance.

Check back Thursday for a clearer idea on the specific timings and sizes.

Eastern Indonesia:

Easing S/SW swell tomorrow as an inconsistent, long-range SW groundswell arrives into the afternoon, peaking Thursday to 4-5ft across exposed breaks.

Easing surf Friday and Saturday.

Small-moderate sized, mid-period S/SW swell building Sunday afternoon, reaching 3-5ft across exposed breaks, easing Monday with a secondary similar sized pulse for Tuesday afternoon, easing Wednesday/Thursday.

Possible moderate sized mid-period S’ly swell Friday, ahead of a stronger groundswell the following weekend.

Variable, light, locally offshore morning winds ahead of weak, onshore afternoon breezes.

Uluwatu 16-day Forecast Graph/WAMs

Western Indonesia/Mentawais/South Sumatra:

Long-range SW groundswell building tomorrow, reaching 4-5ft+ into the afternoon, easing from a similar size Thursday.

Smaller, mid-period S/SW swells for the period.

Building mid-period W-W/NW swell from Friday but more so into the weekend, reaching 6ft or so, easing slowly next week.

Variable winds today and tomorrow, freshening from the NW later Thursday, and then SW to W/NW on Friday depending on location.

Varying winds next week out of the northern quadrant, dependant on the position of the deepening lows axis.

Mentawai 16-day Forecast Graph/WAMs

Maldives:

Moderate sized, inconsistent S’ly and S/SE swells this afternoon, tomorrow and Thursday morning to 3-5ft across the southern atolls (smaller Male), easing from Friday.

Moderate + levels of SE trade-swell building slowly on the weekend, peaking next week to at least 4ft across exposed breaks, if not more later week/the following weekend.

E/NE winds across northern and central locations tomorrow through Saturday, W’ly to the south.

Winds tending more N’ly across northern and central locations from Sunday, freshen NW to the south with strengthening W-W/NW winds next week.