Southern Ocean storm

49°17.2′S 156°00.7′W

Waves left about 18 Sep 00:48Z, ± 16 h

Placed by 2 buoys, whose own placements lie within 370 nmi of it

Each buoy places the storm from how its swell's period shortened as it arrived: the longest waves travel fastest. Fronts are drawn at deep-water group speeds along great circles, and stop at land. How it is worked out