Characteristics and development of European cyclones with tropical origin

Using the Modern-Era Retrospective analysis for Research and Applications (MERRA) reanalysis data set for the period 1979-2013, the characteristics of cyclones originating from the tropics that reach western Europe have been analyzed. Four different life cycles have been identified, that differ in structure during the tropical phase, extratropical transition and final development when they reach Europe. The strongest storms that reach Europe are warm seclusion cyclones. They are characterized by a warm core and a frontal T-bone structure. Rapid deepening occurs in the latest phase, around their arrival in Europe. A recent modeling study that has been reported earlier suggests that warm seclusion storms might become a serious threat for Europe in a warmer climate. The strong similarity between the observed and simulated storms supports the physical arguments for this statement.