LARGEST (CIRCUMFERENCE) HAILSTONE EVER RECORDED . But while the US set the record for the longest distance, France experienced the longest-lasting lightning strike ever, according to the WMO, with a flash over the Cote d'Azur region in 2012 lighting up the sky for an incredible 7.74 seconds - prior to the event, lightning was thought to max out at 1 second. Canada’s largest hailstone of record was that collected at Cedoux, Saskatchewan on August 27, 1973. The storm is also the second most intense Pacific typhoon ever. This was sampled by the Eldora radar during BAMEX operations, and Roger Wakimoto has a few slides from preliminary analysis of the event starting here: https://brobible.com/culture/article/longest-lightning-strike-ever-440-miles Advertisement On June 20, 2007, during a thunder storm in Oklahoma, a lighting bolt streaked across half the state. Typhoon Tip is the largest storm by diameter in world history. Not sure on total storm size, but the largest documented mesocyclone on record may be the Superior NE supercell from June 22, 2003 (the same day and just south of the famous Aurora hail event). The hurricane was a tropical cyclone for 27.75 days, according to NOAA HRD, claiming an estimated 3,369 lives in Puerto Rico, the island's deadliest hurricane on record. The storm’s gale winds would cover the Western United States from the Pacific Coast to the western border of Missouri. It measured 114 mm in diameter (4.5”) and weighed 290 grams (10.2 ounces). A look at the lightning “megaflash” and satellite image of the storm that produced the world's longest certified lightning discharge on Oct. 31, 2018. Tip formed over the Marshall Islands near the Philippines. The longest reported duration of a continual lightning strike was in Provence-Alpes-Côte d'Azur in southern France in 2012, when a storm saw a single strike last for 7.74 seconds. Aurora, Nebraska – June 22nd, 2003 . A 2018 storm over Brazil set the record for longest flash by distance, while another storm over Argentina in 2019 produced the longest-enduring flash in terms of time. An 18.75 inches (47.6 cm) circumference hailstone was recorded on June 22nd, 2003 on a severe thunderstorm that hit Aurora, Nebraska, United States.