North Pacific storm

48°36.7′N 146°23.1′W

Waves left about 27 Sep 01:05Z, ± 2 h

Placed by 8 buoys, whose own placements lie within 313 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