The AVAMET Network and the Exceptional Precipitation Event of October 2024 in the Valencian Country (Eastern Iberia)

The Valencian Country was struck by a catastrophic torrential rainfall event on October 29th, 2024, resulting in deadly flash floods. More than 225 casualties were reported in the metropolitan area of València, resulting in the deadliest climate-related disaster of the Iberian Peninsula in the last few decades. This event joins a list of flood-related disasters that have impacted the region in the past. Most of these events were triggered by cut-off lows situated over Southern Iberia or Northern Africa, and the 2024 event was not an exception.

The Event of October 2024, as others in the past, was caused by a stationarity mesoscale convective system, which produces up to 720 mm in less than 12 hours. The precipitation field showed exceptional spatial variability and was confined to a narrow-longitudinally and long-latitudinally geographical band, with precipitation gradients greater than 500 mm in less than 20 km. In such a meteorological context, almost real-time data and a high-densely network of rainfall measure is crucial to manage the evolution of the accumulated precipitation field and subsequent flash floods and derived impacts.

The Meteorological Valencian Association (AVAMET), with more than 700 members throrought the Valencian territory, was born in 2011 as a non-profit meteorological amateur society. Among the objectives of the association are deepening the knowledge of meteorology and climatology, providing high-quality meteorological data to society, and promoting collaboration with other public entities Furthermore, many Valencian municipalities have joined AVAMET during the last few years in order to have local real-time quality meteorological data. The AVAMET real-time network of nearly 750 rainfall gauges is co-existing with others derived from government organizations. The quality control is guaranteed by memberships and internal quality control, thus each automatic rain gauge from the network is complemented by a manual one.

Despite being one of the best monitored areas in the Mediterranean area, the event occurred in Valencian Country produced an extraordinarily high number of fatalities, which is difficult to justify. This underscores the necessity of establishing reliable communication mechanisms to ensure that weather-related information effectively reaches the general population, in order to prevent miscommunication or incomprehensible failures in civil protection warnings.