Bluegraph
SIMarineUS

Storms placed by their swell

North Pacific storm

45°11.6′N 143°57.2′W

Waves left about 26 Sep 06:58Z, ± 3 h

Placed by 2 buoys, whose own placements lie within 221 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