Fun waves over the coming days, slow next week until the weekend

Craig Brokensha picture
Craig Brokensha (Craig)

Bali and Mentawais forecast​​​​​​ by Craig Brokensha (issued Thursday 6th July)

Best Days: Friday through Tuesday morning, exposed breaks each morning from Wednesday until next weekend

This week and next (Jul 7 - 14)

Bali: The surf is small this morning, but a new long-range S/SW groundswell is due to build this afternoon and peak tomorrow morning.

The polar low that generated this swell was very strong but distant, hanging close to the polar shelf in the Heard Island region.

With this the waits between sets will be considerable with a slow increase this afternoon, reaching 5-6ft on the sets by dark, with tomorrow seeing 6ft to occasionally 8ft waves at magnets, easing through the day.

The swell should steady Saturday ahead of some new S/SW groundswell Sunday, followed by a reinforcing and less consistent increase Monday.

These swells have been generated by back to back polar fronts, the first projecting up into WA, generating some mid-period swell for Sunday to 6ft at exposed breaks (our models are incorrectly combining a small long-period swell with the mid-period energy).

Monday's swell will be a little stronger, with a good polar low forming east of Heard Island generating a fetch of gale to severe-gale W/SW winds, weakening into today.

This swell will be less consistent compared to Sunday's but should keep good 6ft sets hitting exposed breaks through Monday, easing off into Tuesday and Wednesday.

Now, winds over the coming period will tend a little more SE, which will favour most protected spots. Early each morning more variable winds are due.

We should see straighter E/SE trades kick back in early-mid next week, strengthening late week.

Into the end of the week small inconsistent background SW and S/SW swells will prevent exposed coasts going flat with infrequent 3-5ft sets due Thursday and Friday.

A flurry of stronger polar frontal activity between Heard Island and WA early next week should generate some larger S/SW groundswell energy into next weekend.

We'll see back to back fetches of gale to severe-gale W'ly winds generated through our southern swell window, producing a few different pulses of S/SW groundswell, likely coming in between 6ft to possibly 8ft Saturday, easing slowly through Sunday. We'll have a closer look at this Tuesday though.

16 day Bali Forecast Graph
16 day East Java Forecast Graph
16 day Sumbawa Forecast Graph

Ments: Small waves this morning, but a new inconsistent S/SW groundswell should arrive later today, reaching 4-6ft at south magnets before dropping back from a similar size tomorrow morning.

The S'ly swells impacting Bali over the weekend and early next week will only be generated late in our swell window, and come in under the size of a better long-range SW groundswell.

This groundswell was generated by a tight but intense polar low forming south of South Africa over the weekend. There's been no change to the expected size from this swell, with inconsistent 5ft sets due to develop into Saturday afternoon/evening, easing from a similar size Sunday morning.

There's still nothing major due next week with the storm track remaining benign in our swell window through this weekend and early next week.

Exposed breaks are due to offer infrequent 3ft to sometimes 4ft at the swells low point Tuesday and Wednesday morning.

A small kick in size is likely Thursday but into the weekend some fun S'ly swell spreading up off the activity between Western Australia and Heard Island is expected.

South magnets should see sets developing to 6ft, easing back slightly Sunday and further Monday.

Winds are due to be variable throughout the coming period, taking a slight S/SE tendency mid-next week.

16 day Mentawai forecast graph
16 day Nias forecast graph
16 day South Sumatra forecast graph