North Pacific storm

26°06.5′N 145°37.6′W

Waves left about 27 Sep 00:59Z, ± 6 h

Placed by 2 buoys, whose own placements lie within 61 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