North Pacific storm

37°27.7′N 169°33.4′E

Waves left about 24 Sep 16:48Z, ± 6 h

Placed by 2 buoys, whose own placements lie within 287 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