North Pacific storm

50°06.2′N 173°47.2′W

Waves left about 24 Sep 22:12Z, ± 2 h

Placed by 13 buoys, whose own placements lie within 351 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