North Atlantic storm

44°31.8′N 063°59.3′W

Waves left about 22 Sep 03:02Z, ± 4 h

Placed by 4 buoys, whose own placements lie within 226 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