North Pacific storm

46°33.1′N 132°56.4′W

Waves left about 28 Sep 07:19Z, ± 2 h

Placed by 3 buoys, whose own placements lie within 194 km 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