Hurricane Calvin was a powerful and long lived category 3 hurricane that caused windy gusts and high rainfall in Hawaii during mid July. The third named storm, third hurricane, and first major hurricane of the 2023 Pacific hurricane season, Calvin caused of rainfall at Honolii Stream. Calvin formed from an area of low pressure off the coast of Southern Mexico on July 7. The low became better organized and was designated, Tropical Depression Three-E. In favorable conditions over the next several days, the depression strengthened and was upgraded to Calvin. Calvin rapidly intensified during July 13-14 and was classified as the first major hurricane of the 2023 Pacific hurricane season. Weakening insued after that and Calvin crossed the 140th meridian into the Central Pacific basin. Calvin later made landfall in Hawaii as a minimal tropical storm causing heavy rainfall before becoming post tropical on July 19.
Meteorological History
An area of low pressure formed off the coast of Southern Mexico on July 7. The disturbance became better organized over the course of several days, and developed a well-defined center on the afternoon of July 11, becoming Tropical Depression By early the next day, the depression had begun developing a central dense overcast, and exhibiting banding features, and so was upgraded with the 09:00 UTC advisory, becoming Tropical Storm Calvin. Calvin moved westward out to sea within a favorable environment with low wind shear and warm sea surface temperatures, and was upgraded to a Category 1 hurricane at 15:00 UTC on July 13. It then rapidly intensified and became the season's first major hurricane at 15:00 UTC on July 14. It had a well-defined eye at the time, with a pronounced ring of deep convection surrounding it. A weakening trend began later that day, and by early on July 16, the system had fallen to tropical storm strength. Still moving generally westward, the storm crossed the 140th meridian at around 15:00 UTC on July 17, thus entering the central Pacific basin; its sustained winds at the time were near 50 mph (85 km/h). Then, early on July 19, Calvin passed just south of the Island of Hawaii. Weakened by the close encounter with land, the storm began losing its tropical characteristics. Calvin became post-tropical by 21:00 UTC on July 19.
Preparations and impact
All state parks on the Big Island, as well as most of Hawaiʻi Volcanoes National Park, were shut beginning the afternoon of July 18, while public schools were closed for the whole of July 19. Eight emergency shelters were opened across the county on July 18. Calvin caused no significant damage; only minor flooding occurred in flood-prone areas of the Big Island. Rainfall reached up to at Honolii Stream, while peak gusts of and were recorded on the summits of Haleakalā and Mauna Kea, respectively.
See also
Weather of 2023
Tropical cyclones in 2023
List of Category 3 Pacific hurricanes
List of Hawaii hurricanes
Hurricane Dora (2023) – Another major hurricane that indirectly impacted Hawaii weeks after Calvin