North Pacific storm

34°44.3′N 174°08.2′E

Waves left about 31 Aug 20:56Z, ± 4 h

Placed by 2 buoys, whose own placements lie within 499 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