Hurricane Gonzalo and its Extratropical Transition to a Strong European Storm

摘要: Introduction. Recent studies simulating continued anthropogenic climate change provide evidence that extratropically transitioning tropical cyclones (TCs) will become more frequent and hit western Europe often (Baatsen et al. 2015; Haarsma 2013). Mokhov (2014) asserted, “Under the tendency towards global warming, we can expect an increase in number of intensive warmer humid troposphere.” We saw Hurricane Gonzalo 2014 as occasion to assess if these aforementioned properties transitioned storms—frequency, intensity, tracks—have changed. East Leeward Islands a depression formed on 12 October 2014. On its way it passed through northern intensified category 4 hurricane (Saffir-Simpson wind scale) 16 October, known “Gonzalo”. After changing direction northeast, weakened crossed Bermuda with gusts than 200 km h−1 heavy rains about 70 mm within 24 hours. 19 storm extratropical cyclone off coast Newfoundland (Brown 2015). While continuing path across North Atlantic northwestern Europe, was absorbed by cold front strengthened again. Afterwards, part United Kingdom 21 Octber. It Sea then central parts went down Balkans. 23 ex-Gonzalo merged another low pressure system led precipitation for several days this region. Maximum between 100 180 h−1, causing surges, were reported from countries1,2,3. In addition, triggered regional amounts 50–100 hours, while advection air sudden temperature drop snowfall some areas. remnants caused fatalities, structural damage, power outages both sides Atlantic4,5. attracted strong media attention affected many countries along path6. There is no general definition transition (ET) TCs (Malmquist 1999). Basically, gradual transformation TC into characteristics moving poleward baroclinic environment higher shear, larger Coriolis parameter, lower sea surface temperatures (Jones 2003). The ET may interact upper-level troughs or systems. Evans Hart (2003) describe warm-core interacts midlatitude develops core. Forty-six percent 1950 1996 (Hart 2001). This result supported Jones 1970–99 1970–2012 who found 45% underwent ET. But only very few