Gulf of Alaska storm

52°51.2′N 158°47.7′W

Waves left about 15 Sep 09:27Z, ± 2 h

Placed by 4 buoys, whose own placements lie within 171 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