North Pacific storm

11°49.7′N 156°10.2′W

Waves left about 27 Sep 11:26Z, ± 3 h

Placed by 2 buoys, whose own placements lie within 307 mi 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