Hilda (2015)

Hilda formed from a tropical wave that moved into the eastern North Pacific and became a tropical depression at 0000 UTC 6 August 2015 about 1,300 nautical miles west-southwest of Cabo San Lucas, Mexico. It became a tropical storm later that day and then underwent rapid strengthening on 7–8 August as it moved west into the central Pacific. Hilda turned northwestward and then west-southwestward as upper-level winds and drier air weakened it, became a remnant low by 0000 UTC 14 August, and dissipated a day later. Its track stayed well south of the Hawaiian Islands, passing about 165 nautical miles south-southeast of South Point on the Big Island at closest approach on 13 August.

Hilda did not make landfall. A tropical storm watch was issued for the southern portion of the Big Island of Hawaii on 11 August when forecasts showed a possible direct pass, but Hilda weakened and passed to the south without producing tropical-storm-force conditions on land; the watch was cancelled at 0300 UTC 13 August.

Hilda’s peak intensity occurred around 1800 UTC 8 August 2015. The storm reached maximum sustained winds of 125 knots (about 144 mph) with an estimated minimum central pressure of 937 mb, making it a high-end Category 4 hurricane at peak. Earlier that day in the eastern Pacific the storm’s peak was estimated at 100 kt (100 knots) by some agencies, but the best-track peak used for the central Pacific was 125 kt at 1800 UTC 8 August.

Coastal and marine impacts near Hawaii were limited. One buoy (NDBC 51004, about 205 n mi southeast of Hilo) observed sustained winds of 37 kt with a peak gust of 45 kt and seas 12–13 ft on 13 August. East-facing shores of Maui and the Big Island experienced high surf in excess of 16 ft with minor coastal inundation reported. There were no reports of large rainfall totals tied to Hilda in the central Pacific portion of its path reported in the official record.

There were no reported deaths or damage attributed to Hilda. Forecasts generally captured the storm’s formation well, but many models and the forecasts struggled with Hilda’s rapid intensification and subsequent changes in intensity and recurvature; track and especially intensity forecast errors were larger than recent averages during the storm’s rapid changes.