North Atlantic storm

34°32.0′N 066°23.2′W

Waves left about 29 Sep 13:50Z, ± 2 h

Placed by 3 buoys, whose own placements lie within 189 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