Hurricane Daniel (2006)

Hurricane Daniel was the second strongest hurricane of the 2006 Pacific hurricane season. The storm affected Hawaii late in its lifetime, causing moderate rainfall and minor damage. The fourth named storm, third hurricane, and second major hurricane of the season, Daniel originated on July 16 from a tropical wave off the coast of Mexico. It tracked westward, intensifying steadily to reach peak winds of 150 mph (240 km/h) on July 22. At the time, the characteristics of the cyclone resembled those of an annular hurricane. Daniel gradually weakened as it entered an area of cooler water temperatures and increased wind shear, and after crossing into the Central Pacific Ocean, it quickly degenerated into a remnant low on July 26, before dissipating two days later.

Initial predictions suggested that the cyclone would pass through the Hawaiian Islands as a tropical storm; however, Daniel's remnants dissipated southeast of Hawaii. The storm brought light to moderate precipitation to the Island of Hawaii and Maui, causing minor flooding, although no major damage or fatalities were reported.

A tropical wave exited the west coast of Africa on July 2, which crossed into the eastern Pacific Ocean ten days later. Convection increased and slowly organized as the system moved westward, steered by a mid-level ridge. With convective rainbands near an associated low-level circulation, the system developed into a tropical depression late on July 16, located about 525 miles (845 km) south-southwest of Manzanillo, Colima. Conditions favored further development, including warm sea surface temperatures, very low amounts of wind shear, and an established anticyclone. On July 17, the depression strengthened into Tropical Storm Daniel, as outflow improved and banding features developed. The thunderstorms organized into a central dense overcast, and in the center, an eye developed. Late on July 18, Daniel attained hurricane status. It underwent an eyewall replacement cycle, temporarily halting its intensification trend. Daniel restrengthened and attained major hurricane status on July 20. The structure evolved into an annular hurricane, with a large and large eye 30 mi (45 km) in diameter. On July 21, the hurricane underwent another eyewall replacement cycle. Afterward, Daniel attained peak winds of 150 mph (240 km/h) early on July 22, making it a strong Category 4 hurricane on the Saffir-Simpson scale. It maintained peak winds for about 18 hours before weakening due to cooler waters. Daniel entered the Central Pacific on July 24. It decelerated as the ridge to its north weakened, and due to the combination of cool waters and increasing easterly shear, Daniel weakened to a tropical storm on July 25. The thunderstorms dwindled, and Daniel fell to tropical depression status on July 26. A day later, it degenerated into a remnant low, which dissipated just southeast of the Big Island of Hawaii on July 28.^{[1][2][3][4][5][6][7][8][9]}

When Hurricane Daniel was forecast to pass through the Hawaiian islands as a tropical storm, state and Hawaii County officials recommended residents prepare hurricane kits.^[10] The Honolulu National Weather Service issued a high surf advisory for east facing beaches in Hawaii.^[11] The National Weather Service issued a flash flood watch and wind advisory in association with the remnants of Daniel.^[12]

The remnants produced 2–5 inches (50–125 mm) of rainfall throughout windward areas of the Big Island of Hawaii and Maui.^[9] West Wailuaiki on Maui recorded 3.87 inches (98.3 mm) in one day, which was the highest daily rainfall total from the hurricane.^[13] The storm also dropped precipitation on the East Maui watershed.^[14] The rainfall particularly in Kailua-Kona on the Big Island caused ponding on roadways, as well as flooding of small streams.^[15] A station in Ka Lae briefly reported sustained winds of about 35 mph (56 km/h) with gusts to 45 mph (72 km/h).^[9]

• List of Hawaii hurricanes
• Other storms of the same name
• Timeline of the 2006 Pacific hurricane season
• List of Category 4 Pacific hurricanes
• Hurricane Hector (2018) – another strong Category 4 annular hurricane with a similar track.