Hilda (2009)

A tropical cyclone formed from a tropical wave that crossed Central America on 13 August and gradually organized over the eastern Pacific. A westward-moving low formed about 1200 UTC 21 August, and the system became a tropical depression at 1200 UTC 22 August while centered roughly 1,100 nautical miles east‑southeast of the Big Island of Hawaii. The system strengthened to Tropical Storm Hilda about six hours later and moved generally westward across the central North Pacific. Hilda remained well south of the Hawaiian Islands, weakened to a depression by 0000 UTC 27 August, became a remnant low by 1800 UTC 28 August, and finally dissipated late on 31 August about 1,100 nautical miles west‑southwest of Honolulu.

Hilda did not make any landfalls. It stayed over open water to the south of Hawaii for its entire life, and no watches or warnings were required for U.S. or other land areas.

The storm’s maximum sustained winds reached 55 knots (about 63 mph) with a minimum central pressure of 995 mb on 24 August, making its peak intensity equivalent to a moderate tropical storm (below hurricane strength). Hilda’s best‑track record shows it peaked near 14.2°N, 143.6°W on 24 August and then gradually weakened under increasing unfavorable conditions.

There were no reports of storm surge or significant rainfall impacts associated with Hilda. The cyclone remained well offshore and no ships reported tropical‑storm‑force winds. Because it stayed far from land, no specific coastal surge heights or heavy rainfall totals were recorded for cities or counties.

No damage or casualties were reported. Forecasts of Hilda’s formation and track were generally accurate: the system’s genesis was anticipated in outlooks issued up to about two days beforehand, and National Hurricane Center track and intensity errors for Hilda were comparable to or lower than recent five‑year averages, reflecting that its track and intensity were relatively straightforward to predict for this storm.