Bluegraph
SIMarineUS

Storms placed by their swell

Gulf of Mexico storm

21°48.5′N 083°29.5′W

Waves left about 22 Sep 15:01Z, ± 6 h

Placed by 2 buoys, whose own placements lie within 110 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