Tropical cyclones require high SSTs, instability and deep moist convection in order to form and intensify. The genesis conditions related to tropical cyclones in the Southern Hemisphere have been derived from global and historic studies, which by their generalist nature may conceal the true magnitudes of climate variables required for tropical cyclogenesis. This study updates and re-examines the previous tropical cyclone climatology with reference to the canonical works of Gray (1968, 1979). The optimal and minimum ranges of thermodynamic and dynamic climate variables following tropical cyclogenesis were determined, to define the conditions at which the majority of Southern Hemisphere tropical cyclones attain cyclone intensity. The SSTs of 27.5–28.5 °C is observed as the optimal range at which a majority of storms undergo genesis. However, the lowest observed magnitude at which cyclonic intensification was possible is 24 °C. This challenges the 26.5 °C threshold for genesis in the Southern Hemisphere. Based on factor analysis weightings and multivariate regression, SST, air temperature, geopotential height, components of vertical shear (u-wind) and relative humidity also account for a relatively large amount of variability in the intensification of tropical cyclones. Omega at the 1000 mb level and SST at the point of maximum intensity is important in promoting high magnitude storm intensification when initial SST during storm genesis is lower than 27.3 °C.

热带气旋需要高海温、不稳定和深层潮湿对流才能形成和加强。与南半球热带气旋相关的发生条件来自全球和历史研究，由于其通用性，这些研究可能掩盖了热带气旋发生所需气候变量的真实大小。本研究参考格雷（1968、1979）的经典著作，更新并重新审视了先前的热带气旋气候学。确定了热带气旋发生后热力学和动态气候变量的最佳和最小范围，以定义大多数南半球热带气旋达到气旋强度的条件。27.5–28.5 °C 的 SST 被观察为大多数风暴发生的最佳范围。然而，观测到的气旋可能增强的最低震级为 24 °C。这挑战了南半球 26.5 °C 的起源阈值。基于因子分析权重和多元回归，海温、气温、位势高度、垂直切变（u-wind）分量和相对湿度对热带气旋的强度也有较大的影响。当风暴发生期间的初始 SST 低于 27.3 °C 时，1000 mb 级别的 Omega 和最大强度点的 SST 对于促进高强度风暴增强很重要。气温、位势高度、垂直切变（U 型风）分量和相对湿度也是热带气旋增强中相对较大的可变性因素。当风暴发生期间的初始 SST 低于 27.3 °C 时，1000 mb 级别的 Omega 和最大强度点的 SST 对于促进高强度风暴增强很重要。气温、位势高度、垂直切变（U 型风）分量和相对湿度也是热带气旋增强中相对较大的可变性因素。当风暴发生期间的初始 SST 低于 27.3 °C 时，1000 mb 级别的 Omega 和最大强度点的 SST 对于促进高强度风暴增强很重要。