North Atlantic storm

22°24.8′N 025°50.8′W

Waves left about 21 Sep 01:39Z, ± 6 h

Placed by 2 buoys, whose own placements lie within 283 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