North Atlantic storm

36°02.0′N 055°55.7′W

Waves left about 29 Sep 06:44Z, ± 3 h

Placed by 2 buoys, whose own placements lie within 270 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