North Pacific storm

44°40.1′N 169°43.2′W

Waves left about 25 Sep 02:29Z, ± 2 h

Placed by 10 buoys, whose own placements lie within 334 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