Differentiating lightning in winter and summer with characteristics of the wind field and mass field

Abstract. Lightning in winter (December–January–February, DJF) is rare compared to lightning summer (June–July–August, JJA) central Europe north of the Alps. The conventional explanation attributes scarcity seasonally low values variables that create favorable conditions summer. Here we systematically examine whether different meteorological processes are at play winter. We use cluster analysis and principal component find physically meaningful groups ERA5 atmospheric reanalysis data for northern Germany. Two thunderstorm types emerged: wind-field thunderstorms CAPE (convective available potential energy) thunderstorms. Wind-field characterized by increased wind speeds, high cloud shear, large dissipation kinetic energy boundary layer, moderate temperatures. Clouds close ground, a relatively fraction clouds warmer than −10 ∘C. convective (CAPE), presence inhibition (CIN), temperatures, accompanying amounts water vapor. Large cloud-physics related charge separation such as ice particles or base height further differentiate both originates thunderstorms, whereas mostly only small Consequently, typical weather situations study area Germany strong westerlies with embedded cyclones. For typically on anticyclonic side southwesterly jet.