North Pacific storm

48°57.7′N 143°30.5′W

Waves left about 27 Sep 00:38Z, ± 1 h

Placed by 9 buoys, whose own placements lie within 267 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