Abstract Thermodynamic indices have been used as a tool for nowcasting thunderstorms for decades. The present study deals with understanding the variations in threshold values of various thermodynamic indices during pre-monsoon season at two north-eastern Indian stations: Agartala and Guwahati. The study utilises thirty years (1987–2016) of radiosonde data, surface information about thunderstorms, and TRMM daily rainfall data. The threshold values for five years period interval each has been determined for fourteen thermodynamic indices to the whole period. The indices related to latent, potential and convective instability responded differently at both the sites.

中文翻译：

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季风前雷暴期间印度东北部两个热带站的热力学指数阈值趋势

摘要 几十年来，热力学指数一直被用作临近预报雷暴的工具。本研究旨在了解印度东北部两个站点：Agartala 和 Guwahati 在季风季节期间各种热力学指数阈值的​​变化。该研究利用了三十年（1987-2016 年）的无线电探空仪数据、有关雷暴的地表信息和 TRMM 日降雨量数据。已经为整个时期的 14 个热力学指标确定了每个五年周期间隔的阈值。与潜在的、潜在的和对流不稳定性相关的指数在两个地点的反应不同。