North Pacific storm

14°26.2′N 150°38.2′W

Waves left about 7 Sep 16:06Z, ± 2 h

Placed by 5 buoys, whose own placements lie within 165 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