Hawaiian Record Hail and Tornado Event of March 9, 2012

This presentation will focus on the March 9, 2012, supercell thunderstorm that hit the island of Oahu and set the record for the largest hailstone on record for the state. The hailstone was roughly the diameter of a grapefruit and measured 4.25 inches long, 2.25 inches tall and 2 inches wide. The previous record hailstone was 1 inch. The record-setting hailstone was dropped by a “supercell” thunderstorm on the windward side of Oahu that also produced large hail in Kaneohe and Kailua. Numerous reports of hail with diameters of 2 to 3 inches and greater were reported. The National Weather Service investigated a hailstone reportedly larger than 3 inches in diameter, which was collected by a resident in the Aikahi neighborhood of Kailua. Upon inspection, it was apparent the stone was much larger.

Supercells can also produce tornadoes, another rarity in Hawaii. The same hail-producing supercell produced a confirmed EF-0 tornado with winds of 60-70 mph in Lanikai and Enchanted Lakes on Oahu.