Hurricane Cosme (2007)

Hurricane Cosme

Category 1 hurricane (SSHWS/NWS)
Hurricane Cosme at peak intensity on July 16
Formed	July 14, 2007
Dissipated	July 22, 2007
Highest winds	1-minute sustained: 75 mph (120 km/h)
Lowest pressure	987 mbar (hPa); 29.15 inHg
Fatalities	None reported
Damage	Minimal
Areas affected	Hawaii
Part of the 2007 Pacific hurricane season

Hurricane Cosme was a minimal hurricane that threatened Hawaii in mid-July 2007. The sixth tropical cyclone, third named storm and first hurricane of the 2007 Pacific hurricane season, Cosme originated from a tropical wave that emerged off the coast of Africa on June 27 and tracked westward before emerging in the eastern Pacific. A system along the wave organized, and it was classified as a tropical depression on July 14, a tropical storm on July 15, and a hurricane on July 16. Cosme reached peak intensity as a Category 1 hurricane on the Saffir-Simpson Hurricane Scale, but quickly weakened due to cooler waters. Steadily decreasing in strength, the storm was downgraded to a tropical depression before passing to the south of the Hawaiian Islands. The depression crossed into the Central Pacific and degenerated into a remnant low by July 23.

Because Cosme stayed far from land, effects were mostly minor. Swells up to 9 ft (2.7 m) and up to 6.94 in (176 mm) of rainfall were reported, in addition to wind gusts of 40 mph (65 km/h). No fatalities or injuries were reported, and only minimal damage occurred.

The origins of Cosme can be traced back to a tropical wave that left the coast of Africa on June 27, 2007. Due to a lack of associated convection, the wave was difficult to track across the Atlantic Ocean and Caribbean Sea. The National Hurricane Center (NHC) estimated that the wave emerged into the Pacific Ocean on July 8. Because the system was embedded within the Intertropical Convergence Zone (ITCZ), development was initially slow. However, when it separated from the ITCZ on July 13, the disturbance increased in convective organization, and was classified as Tropical Depression Six-E about midway between Mexico and Hawaii. It tracked westward at 12 mph (19 km/h) due to steering currents of a tropical easterly flow. Although wind shear was generally light, ocean temperatures were only marginal for tropical cyclone intensification. Forecasters experienced difficulty in locating the exact center of circulation. By July 14, convection had steadily decreased, although the storm's movement was initially uncertain due to its location within a broad low pressure area. Early on July 15 the depression's appearance on satellite imagery improved, and at 1800 UTC the NHC upgraded the depression to tropical storm status, and gave it the name "Cosme".