Peak period vs Significant Wave hieght
What location are you looking at?
Sig wave height will always be relatively low (compared to Australia) as the swells have travelled a lot further from their source, and have thus suffered wave decay (so, sig height isn't necessarily a reflection of surf height). But if the swell has a lengthy period, it'll boost wave heights across the surf zone.
Our in-house surf model (not the wave model) does a pretty good job at estimating surf size using significant wave height and period (and direction); feedback fom a large number of users over the last few years has shown that our model performs much better than any other website. So you can feel reasonably confident that the automated surf height estimates are usually pretty close (for exposed spots, obviously).
No worries Ben, I was actually looking at the WAM for Indo (Off to Bali on Thursday). As were a few others as I see. A few of us noticed a very large Peak, with low swell. Craig explained this "20sec Forerunners" earlier in the week. I'm always viewing the ever changing WAMS everyday, and am hoping like Craig said for some moderate Swell on Friday Morning.
For a location like indo, would the sig wave height be quiet accurate (as shown on the WAMS) as its a pretty exposed spot, and swells have travelled a long way? + Would the peak period bump this up if its high like you say? haha or am I being to hopeful:)
Sure, significant wave heights are likely quite accurate, but that's only relative to a wave buoy recording it (of which there are none across the region that are publicly available).
So, deep water swells might be 1.5m (sig wave height). But with an 18 second period, this one and half metre ocean swell would jump up to four metres or more on the wave face once it arrives across the surf zone.
But conversely, a larger signifciant wave height would result in a smaller surf size, if the swell period is much smaller.
Hence, why significant wave height doesn't necessarily relate to surf height.
As for Bali, later next week looks like it'll see a strong groundswell (forerunners due Thursday, peak surf size due Friday).
https://www.swellnet.com/reports/indonesia/bali/uluwatu/forecast
Thanks Ben, you certainly got me on the froth now!!
Gday Ben,
A mate and myself are going to indo, we are arriving the 1st of Sept. We have just been looking at the WAMS for this area and are wondering what Swells to expect as the Significant Wave Height seems small in comparison to a very high Peak Period.
Cheers