North Atlantic storm

45°47.9′N 037°41.2′W

Waves left about 26 Sep 18:51Z, ± 4 h

Placed by 3 buoys, whose own placements lie within 278 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