The heavy precipitation event of 14-15 October 2018 in the Aude catchment: a meteorological study based on operational numerical weather prediction systems and standard and personal observations
The heavy precipitation event of 14-15 October 2018 in the Aude catchment: a meteorological study based on operational numerical weather prediction systems and standard and personal observations
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DOI：
10.5194/nhess-21-1135-2021
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发表时间：
2021-03-31
影响因子：
4.6
通讯作者：
Laurantin, Olivier
中科院分区：
文献类型：
--
作者：
Caumont, Olivier;Mandement, Marc;Laurantin, Olivier
从气象角度研究了2018年10月14日和15日导致法国西南部Aude流域严重山洪暴发的强降水事件，使用确定性和概率数值天气预报系统，以及来自标准气象站和个人气象站的独特观测组合。该个例具有地中海强降水事件的典型特征，如其典型的天气形势和持续更新的准静止对流降水，以及一些特殊的特征，如前飓风的存在和先前存在的靠近地面的冷气团。简要回顾了地中海表面温度和土壤湿度的异常，因为它们在这类水文气象事件中起到了作用。一项对降雨预报的研究表明，这一事件的可预测性有限，特别是考虑到所涉及的流域面积很小。结果表明，降水的平稳性与地面附近存在低槽和较强的位势虚温度梯度有关，两者的平稳性通过标准站和个人站的观测相结合来突出。最接近降雨观测的预报包含最温暖、最潮湿和最快的低空急流，并在地面附近模拟了一个槽和一个明显的西部冷空气和东部暖空气之间的边界，这两个边界都是静止的。由哥白尼出版公司代表欧洲地球科学联盟出版。
The case of the heavy precipitation event on 14 and 15 October 2018 which has led to severe flash flooding in the Aude watershed in south-western France is studied from a meteorological point of view using deterministic and probabilistic numerical weather prediction systems, as well as a unique combination of observations from both standard and personal weather stations. This case features typical characteristics of Mediterranean heavy precipitation events such as its classic synoptic situation and its quasi-stationary convective precipitation that regenerates continuously, as well as some peculiarities such as the presence of a former hurricane and a pre-existing cold air mass close to the ground.Mediterranean Sea surface temperature and soil moisture anomalies are briefly reviewed, as they are known to play a role in this type of hydrometeorological events. A study of rainfall forecasts shows that the event had limited predictability, in particular given the small size of the watersheds involved. It is shown that the stationarity of precipitation, whose estimation benefits from data from personal stations, is linked to the presence near the ground of a trough and a strong potential virtual temperature gradient, the stationarity of both of which is highlighted by a combination of observations from standard and personal stations. The forecast that comes closest to the rainfall observations contains the warmest, wettest, and fastest low-level jet and also simulates near the ground a trough and a marked boundary between cold air in the west and warm air in the east, both of which are stationary. Published by Copernicus Publications on behalf of the European Geosciences Union.