North Pacific storm

51°34.2′N 140°06.7′E

Waves left about 21 Oct 09:24Z, ± 4 h

Placed by 3 buoys, whose own placements lie within 276 nmi of it

Its swell is still arriving: last measured at 51000 (Northern Hawaii One) on 29 Oct 07:50Z.

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