The early stages of a tropical cyclone can be a challenge to forecast, as a storm consolidates and begins to grow based on the local and environmental conditions. A high-resolution ensemble of the Hurricane Analysis and Forecast System (HAFS) is used to study the early intensification of Hurricane Dorian, a catastrophic 2019 storm in which the early period proved challenging for forecasters. There was a clear connection in the ensemble between early storm track and intensity: stronger members moved more northeast initially, although this result did not have much impact on the long-term track. The ensemble results show several key factors determining the early evolution of Dorian. Large-scale divergence northeast of the tropical cyclone (TC) appeared to favor intensification, and this structure was present at model initialization. There was also greater moisture northeast of the TC for stronger members at initialization, favoring more intensification and downshear development of the circulation as these members evolved. This study highlights the complex interplay between synoptic and storm scale processes in the development and intensification of early-stage tropical cyclones.

中文翻译：

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通过飓风分析和预报系统（HAFS）的集合了解引起多利安飓风早期加剧的过程

热带风暴的早期阶段可能会是一个挑战，因为风暴会根据当地和环境条件而巩固并开始增长。飓风分析和预报系统（HAFS）的高分辨率合奏用于研究飓风多里安（Dour）的早期强化，这是一场灾难性的2019年风暴，其中早期对预报员而言具有挑战性。在早期风暴轨迹和强度之间的合奏中有明确的联系：较强的成员最初向东北移动，尽管这一结果对长期轨迹没有太大影响。合奏结果显示了决定Dorian早期进化的几个关键因素。热带气旋（TC）东北的大规模散度似乎有利于强化，并且这种结构出现在模型初始化时。TC东北部也有较大的水分，以便在初始化时形成更强的成员，随着这些成员的演化，有利于循环的更多集约化和下降剪切发展。这项研究强调了天气和风暴尺度过程在早期热带气旋发展和加剧过程中的复杂相互作用。