Cosme (2007)

Hurricane Cosme formed from a tropical wave that likely moved into the eastern North Pacific around 8 July 2007. It became a tropical depression on 14 July about 1,725 nautical miles east-southeast of Hilo, Hawaii, strengthened to a tropical storm on 15 July, briefly reached hurricane strength on 16 July, and then weakened. Cosme moved generally westward across the eastern and central North Pacific, crossed 140°W into the Central Pacific basin on 19 July, degenerated to a remnant low late on 22 July, and dissipated by 24–25 July well south of the Hawaiian Islands.

Cosme did not make landfall. Its entire life was over open water and it remained well south of the Hawaiian Islands and Johnston Island while weakening and later dissipating.

The storm’s maximum intensity was 65 knots (75 mph) with a minimum central pressure of 987 mb, reached at 1800 UTC 16 July. Cosme was thus a short-lived Category 1 hurricane at peak intensity and held hurricane status for about six hours before weakening.

No storm surge or heavy rainfall impacts were reported to land because Cosme remained over the open ocean and did not approach populated coastlines. No ship or land station reported sustained winds of tropical storm force in association with Cosme.

There were no reports of damage or casualties associated with Cosme. The regions most affected were only open waters of the eastern and central North Pacific; no coastal impacts were recorded.

Noteworthy items from the analysis: satellite and QuikSCAT data helped identify the brief intensification and the appearance of an eye on 16 July. Forecast track errors for Cosme were lower than long-term averages at most lead times, and intensity forecasts performed better than typical long-term errors because forecasters correctly anticipated the storm’s weakening as it encountered cooler waters and increased wind shear.