Nias, Mentawai, South Sumatra forecast (Thu 10th Apr)

Nias, Mentawai, South Sumatra forecast by Craig Brokensha (issued Thursday April 10th)

Best Days: Saturday onwards

This week and weekend (Apr 10 - 13)

Small levels of background groundswell will persist through tomorrow but into Saturday a new long-range S/SW groundswell is due to fill and reach 3-4ft later in the day and offer slightly larger 5ft bombs into Sunday afternoon.

Winds in general look to be moderate to fresh from the NW tomorrow before easing gradually over the weekend and blowing light to moderate from the W/NW through early next week (variable each morning).

Next week onwards (Apr 14 onwards)

As touched on the last update, the outlook into next week is finally looking on the up with a couple of medium-large S/SW groundswell pulses expected from Wednesday through until the weekend.

The first pulse will be long-range and very inconsistent, generated by a vigorous polar low firing up west of Heard Island Tuesday which has since pushed north-east across the Kerguelen Islands while weakening. This should build slowly through Tuesday and peak Wednesday, reaching 4-6ft at exposed spots in the Ments, 5-6ft in South Sumatra and 4-5ft+ around Nisa.

A secondary weaker system will piggyback on the tail of this initial system, generating a secondary pulse of S/SW groundswell for Friday morning to a slightly smaller size.

Winds should become lighter and more variable through the week with a NW bias creating good, clean conditions.

Longer term we're on target for a large S/SW groundswell Sunday/Monday from a much broader and stronger polar low firing up west of Heard Island next week, but we'll review this again on Tuesday.