Nias, Mentawai, South Sumatra forecast (Thu 27th Feb)

Nias, Mentawai, South Sumatra forecast by Craig Brokensha (issued Thursday 27th February)

Best Days: Friday morning, Monday onwards

Tomorrow and this weekend (Feb 28 - Mar 2)

The good pulses of S/SW groundswell seen the last few days should start to back off today and should continue to ease into the weekend. A slight kick in long-range S/SW swell is due later Saturday and Sunday morning but to no major size.

Next week (Mar 3 - 7 onwards)

The favourable forecast for next week is still on track with a series of long-range but good S/SW groundswells due to ebb and pulse each day.

The strongest but probably least consistent pulse is due Monday afternoon and Tuesday morning generated by a vigorous polar low that formed east of Heard Island a yesterday.

This system started its life as Tropical Cyclone Guito between Madagascar and South Africa, with Guito being absorbed into the westerly storm track and deepening significantly as it reached polar latitudes.

Yesterday afternoon and evening a fetch of 35-55kt W/SW winds were aimed on the periphery of our southern swell window but since then the low has tracked further east-southeast and out of our swell window.

What will result is a long-range, strong but very inconsistent S/SW groundswell that will only impact spots open to the south, with much smaller surf away from these spots. The Ments should see sets to 3-5ft, with larger 4-5ft+ waves to the south and smaller 3ft to occasionally 4ft waves around Nias.

Two additional pulses of slightly more consistent S/SW groundswell are due Wednesday and then Thursday owing to a couple of secondary polar fronts pushing up quickly on the back of the deep polar low.

While not as strong, these two systems will push further north into the Indian Ocean (on the edge of our southern swell window) resulting in more consistency than Monday/Tuesday's swell.

Winds for the most part are expected to be light and variable creating clean, glassy conditions.

Longer term, the next significant swell is expected to arrive next weekend with a couple of long-range pulses on the cards. We'll discuss this more next Tuesday though.