Thu, 15 August 2019

A scarcely believable 21 second south swell is set to slam into SA from Friday into Saturday, forecasts Spike as he surveys some serious southern ocean carnage.


23 SECONDS! This is the swell that hits Indo next Wednesday after hitting SA on Friday. Photo Windy

The entire southern ocean is boiling with a series of crazy low pressure storms, testimony to the inter-seasonal volatility that often sits on the cusp of winter and spring-time.

We have swell for days and days, with the Cape gratefully receiving the swell tomorrow, Friday, and it spreads up the East Coast overnight into Saturday, the underlying long period eventually manifesting itself as the swell propagates further from the originating storm.

Period is a function of wind velocity and denotes the speed of the swell, and 21 seconds is a pretty fast moving swell. In fact, in the deep ocean, that means speeds of almost 120 km/h (for the individual swell). Of course, the sets travel at half the speed.

Yes, they do. But I dont' have time to explain. I am in a coffee shop waiting for a ride to go surfing cooking waves tomorrow.


925 MB! A super powerful storm sucks up a massive tract of the ocean on Monday. Photo Windy

Anyhoo, suffice to say that the storm behind the storm packed wind speeds of 65kts or more along a big fetch pointing straight up towards our lovely country. At the moment, today, the storm has eased to 952mb and still spewing out 15 metre swells at 18 seconds.

This swell, by the way, arrives in Indo at 23 seconds (the models read 18 but it's actually 23), on Tuesday and Wednesday next week. Oh my hat. A 4m swell at 23 seconds in Indo. What is that? What does it mean? Well it means it was 23 seconds from the start.

As I said, no time to explain. So back to this swell. Best time for the southern Cape is Friday tomorrow to surf it. Saturday is onshore. Best time for upper East Coast is early Saturday, when the obligatory katabatic offshore wind will deliver ridiculous conditions, if you have planned very carefully which spots will cope with the some on energy and water moving around.

By Sunday, game over. A stiff NE blows down the coast, although a coastal low in the western Cape will start to create another west switch, and more epic surf.

And then, by the way, more ridiculousness ahead. Two strong low pressure cells of 970 and 980 form WSW and SSW of Cape Town on Sunday and by Monday lunch time, they have gradually morphed into one gigantic 924mb storm.

The fetch area is flippin' enormous bru. Waves for days!

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