North Pacific storm

40°51.1′N 166°23.5′W

Waves left about 30 Aug 16:11Z, ± 6 h

Placed by 2 buoys, whose own placements lie within 382 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