Further strengthening ensued, and Felicia peaked in intensity as a Category 4 hurricane with sustained winds of 145 mph (233 km/h) and a barometric pressure of 935 mbar (hPa; 27.61 inHg).

On August 11, Felicia weakened to tropical depression status, and soon degenerated into remnant low just prior to passing over the islands.

Hurricane Felicia originated from a tropical wave that moved off the west coast of Africa into the Atlantic Ocean on July 23, 2009.

The system remained ill-defined until August 1, at which time convection began to increase and the wave showed signs of organization.

[1][8] Located within an area of low wind shear and high sea surface temperatures, averaging between 28 and 29 °C (82 and 84 °F),[3] the storm quickly developed, with deep convection persisting around the center of circulation.

These conditions were anticipated to persist for at least three days; however, there was an increased amount of uncertainty due to possible interaction with Tropical Storm Enrique.

[11] Late on August 4, the intensity of Felicia led to it taking a more northward turn in response to a mid- to upper-level trough off the coast of the Western United States.

[13] Maintaining a well-defined eye, Felicia neared Category 4 status[14] and hours later, the storm attained winds of 140 mph (230 km/h) and a pressure of 937 mbar (hPa; 27.67 inHg) during the evening hours, making it the strongest Pacific storm east of the International Date Line since Hurricane Ioke in 2006[1][15] and the strongest in the eastern Pacific basin since Hurricane Daniel of 2006.

[1][2] Around 5:00 pm PDT (0000 UTC August 6) Felicia reached its peak intensity with winds of 145 mph (233 km/h) and a minimum central pressure of 935 mbar (hPa; 27.61 inHg).

[17] Early the next day, the structure of the hurricane quickly deteriorated as convection became asymmetric and cloud tops warmed significantly.

[20][21] Around 11:00 am HST (2100 UTC), the Central Pacific Hurricane Center (CPHC) took over responsibility of issuing advisories as Felicia crossed longitude 140°W.

[26] Several hours after being downgraded, the CPHC issued its final advisory on Felicia as it degenerated into a remnant low near the Hawaiian Islands.

[42] On August 6, the Red Cross stated that it was deploying a disaster recovery team, led by the director of the agency, to the islands of Hawaii.

[43] On August 7, five Hurricane Hunter planes were dispatched to Hickam Air Force Base to fly missions into the storm.

[44] Later that day, the Central Pacific Hurricane Center issued tropical storm watches for the island of Hawaii, Maui, Kahoolawe, Lanai, and Molokai.

[46] The watches for the Big Island were later cancelled as the forecast track appeared to drift further north toward Maui County and Oahu.

[50] In Oahu, areas on the windward side of the island received more than 1 in (25 mm) of rain on August 12 from the remnants of Felicia, causing many roads to become slick.

[64] Officials were forced to close the beaches along Hanauma Bay after swells from Felicia pushed an estimated 2,000 Portuguese Man o' War siphonophorae into the region.