North Pacific storm

25°25.1′N 168°22.3′W

Waves left about 24 Sep 05:20Z, ± 4 h

Placed by 3 buoys, whose own placements lie within 172 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