Loke — 2015

Loke formed from a disturbance in the central Pacific and became Tropical Depression Four‑C on 21 August 2015 about 1,100 nautical miles west‑southwest of the main Hawaiian Islands. The system moved generally northward with some turns and changes in speed, becoming Tropical Storm Loke late on 21 August, weakening briefly to a depression on 22 August, and re‑strengthening to a storm early on 23 August. Loke intensified to a hurricane on 24 August, moved over the western central Pacific and through the Papahanaumokuakea Marine National Monument area between Lisianski Island and Pearl and Hermes Atoll, and began losing tropical characteristics on 26 August as it was absorbed by a large extratropical low. The tropical cyclone dissipated as it crossed the International Date Line by 0000 UTC 27 August. Loke did not make any landfalls on the main Hawaiian Islands or other permanently populated islands. It passed over parts of the Papahanaumokuakea Marine National Monument (including the area between Lisianski Island and Pearl and Hermes Atoll) as a hurricane during the early part of 25 August. Tropical storm and hurricane watches and warnings were issued for Midway Island and for the region from Pearl and Hermes Atoll to Lisianski Island, with a hurricane warning in effect for Pearl and Hermes Atoll to Lisianski Island for a period on 24–25 August. The storm’s peak intensity was 65 knots (75 mph) with a minimum central pressure of 985 millibars, corresponding to a Category 1 hurricane on the Saffir–Simpson scale. The strongest sustained winds at the best‑track peak (25 August 1200 UTC position) were 65 kt (75 mph). There were no reports of storm surge heights or significant rainfall totals in populated areas in the official report. Loke remained largely over open water; the only permanent weather station in the affected monument area is Midway Island, which was issued watches and warnings but did not report notable surge or rainfall impacts in association with Loke in the report. No deaths or damage were reported in connection with Loke. The report notes the storm’s relatively unusual northward and undulating track in the western central Pacific and that its genesis was poorly anticipated by forecasts (the system was first given only a low probability of development within 48 hours). Forecast track errors were typical through 48 hours but were larger than average beyond 48 hours, while official intensity forecasts performed well relative to guidance beyond 48 hours.