Summer heatwaves and extended dry spells create optimal meteorological conditions for occasional dry thunderstorms to produce simultaneous lightning-ignited wildfires (LIW). Concurrent ignitions put a significant burden on the firefighting's initial attack, potentially allowing incipient LIWs to escape and grow into large fires. While we can reasonably forecast lightning activity, predicting dry thunderstorm conditions and potential LIW outbreaks remains challenging. In the present study, we analyze the meteorological factors associated with a LIW outbreak that took place in Catalonia on 15 June 2022, with 22 LIW reported in three consecutive days. The fire hazard was high, but not different from past LIW episodes. ERA5-derived indices related to low-level moisture showed extreme values compared to previous studies. Atmospheric conditions with an elevated lifting condensation level coupled with the synoptic framework were set for the formation of dry thunderstorms. Radar reflectivity profiles revealed sub-cloud evaporation, and rain-gauge records corroborated the occurrence of dry lightning. In the context of global warming, we expect an increase in the frequency of LIW outbreaks in the European Mediterranean region due to an increase in lightning-ignition efficiency, which refers to the average chance of fire per lightning stroke.

中文翻译：

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与干燥雷暴和同时闪电点燃的野火相关的气象因素：2022 年 6 月 15 日在加泰罗尼亚爆发的疫情


夏季热浪和长时间的干旱为偶尔的干燥雷暴创造了最佳的气象条件，同时产生闪电点燃的野火 （LIW）。同时发生的点火给消防的初始攻击带来了沉重的负担，可能会使初期的 LIW 逃脱并发展成大火。虽然我们可以合理地预测闪电活动，但预测干燥的雷暴条件和潜在的 LIW 爆发仍然具有挑战性。在本研究中，我们分析了与 2022 年 6 月 15 日在加泰罗尼亚发生的低油炸裂疫情相关的气象因素，连续三天报告了 22 起低排放鳍。火灾危险很高，但与过去的 LIW 事件没有什么不同。与以前的研究相比，与低水平水分相关的 ERA5 衍生指数显示出极值。大气条件升高的凝结水平加上天气框架为干燥雷暴的形成设定了条件。雷达反射率剖面显示云下蒸发，雨量计记录证实了干闪电的发生。在全球变暖的背景下，我们预计欧洲地中海地区低排放风险爆发的频率会增加，因为雷电点火效率（是指每次雷击的平均火灾几率）的提高。