North Pacific storm

49°58.8′N 164°28.3′W

Waves left about 25 Sep 11:07Z, ± 1 h

Placed by 11 buoys, whose own placements lie within 269 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