A tropical transition (TT) is the process whereby a baroclinic, high-to-moderate vertical wind shear, extratropical or subtropical cyclone is transformed into a warm-core, low vertical wind shear, tropical cyclone. Thirty TT events were identified over the central and eastern North Atlantic basin during the period 1979–2019. The TT process is here studied from a synoptic storm-centered composite climatology and an environmental classification perspective. The aim is to study their common features and highlight their differences. The storm-centered composite analysis reveals that a westerlies meridional trough with quasigeostrophic forcig acts as precursor. TT environments are characterized by a trough at 300 hPa geopotential and the increase of the 1000–500 hPa thickness, i.e., the system evolves into a warm-core, and a strong anticyclone is located north of the surface cyclone. The transition is accompanied by a large latent heat release which promotes the vertical redistribution of potential vorticity and a reduction of the 850–300 hPa vertical wind shear. The identified TTs in the central North Atlantic predominantly developed in environments with warm sea surface temperatures (> 25 °C) and low-to-moderate wind shear (10–15 m s⁻¹). In contrast, the eastern North Atlantic TTs transitioned in low sea surface temperature values (< 25 °C) and high wind shear (> 15 m s⁻¹). Finally, the statistically significant differences in the environmental classification encouraged further analysis of their environments via storm-centered composites, revealing that eastern North Atlantic cyclones have a more defined extratropical structure, while central North Atlantic cyclones show more tropical characteristics.

热带过渡（TT）是一个斜压、高到中等垂直风切变、温带或亚热带气旋转变为暖芯、低垂直风切变、热带气旋的过程。在 1979-2019 年期间，在北大西洋中部和东部盆地发现了 30 次 TT 事件。这里从以天气风暴为中心的复合气候学和环境分类的角度研究 TT 过程。目的是研究它们的共同特征并突出它们的差异。风暴中心复合分析表明，具有准地转强迫的西风带经向槽是前兆。TT 环境的特点是在 300 hPa 位势处出现槽，在 1000-500 hPa 厚度增加，即系统演化为暖核，强反气旋位于地表气旋以北。这种转变伴随着大量潜热释放，促进了潜在涡度的垂直重新分布和 850-300 hPa 垂直风切变的减少。北大西洋中部已确定的 TT 主要在海表温度温暖（> 25 °C）和中低风切变（10-15 ms）的环境中发展^-1 )。相比之下，北大西洋东部的 TTs 在低海面温度值 (< 25 °C) 和高风切变 (> 15 ms ^-1 ) 中转变。最后，环境分类的统计显着差异鼓励通过以风暴为中心的复合材料进一步分析其环境，揭示北大西洋东部气旋具有更明确的温带结构，而北大西洋中部气旋表现出更多的热带特征。