A large storm currently in progress will send solid southerly swell to Indonesia for the start of next week. This storm will compete with an early July blast as 'swell of the season' so far.
For raw size we need a few variables to align. We want raw power and size in a swell, we need a degree of proximity so that not too much of that size is lost before the reef and depending on our spot of choice, swell direction to deliver power through the final few miles towards often somewhat sheltered coast. This is the second of two swells this season so far to tip the scales at the upper end of the range. The first did this in a somewhat unconventional way, with the power delivered from the storm expanding over a larger southerly fetch, closer to Western Australia than might be typical (See chart below). This swell is more conventional, and while the direction is more southerly than perfect for areas like the Bukit, it's still 8 degrees west of the July swell. While the storm lacks the proximity to make it a true classic for size it's power (seas in excess of 40ft at peak) and this positive direction will mean it should offer some of the largest conditions this season.
As always we like to check and double check our data, in this case the fact that the storm is unlikely to develop closer to the coast is a positive from a forecasting perspective. With the storm already in play we have the opportunity to correlate our forecast model with sea height data from satellite observation. This means that although we're almost a full week out we can have real confidence already in this swell arriving as expected in terms of size and timings. As you can see from the satellite data comparison below the forecast (blue line) and actual sea heights (red line) are bang on target even through the peak of the swell.