Severe storms have killed three people in Spain and broken rainfall records. Vilassar de Dalt, in Barcelona province, recorded 176 litres of rain per square metre in six hours and 226 litres since midnight Friday. Drassanes station logged 202 litres; the Olympic Port observatory measured 50.4 litres in a single day. The victims were an elderly woman in Madrigueras (Albacete) on Saturday and two people in Barcelona on Sunday.
On Monday morning, the Agencia Estatal de Meteorología (AEMET) issued its highest warning, a red alert, for the Barcelona prelitoral. Stationary storms threatened Granollers, where Meteocat reported 92 litres per square metre in under an hour. Catalonia was facing its fifth consecutive day of maximum alerts. By 11:00 on October 5, Granollers had recorded 98 l/m² of rain, including 50 l/m² in just 30 minutes. The episode’s total reached 346 l/m², information from figures confirmed by regional authorities.
Catalan authorities sent an ES-Alert emergency message to residents of Vallès Oriental and Maresme over the risk of sudden flooding. AEMET warned that the Granollers area could receive more than 90 l/m² of rain per hour.
The heaviest rain eased, but danger remained. Nine autonomous communities were under weather warnings. Catalonia, Castilla y León, Castilla-La Mancha and Extremadura faced orange alerts for serious risk; Asturias, the Balearic Islands, Galicia, Madrid and Murcia were under yellow alerts for storms or heavy rain. An isolated high-altitude depression, or 'dana', lingered west of Portugal, sending moisture and energy across Spain. The Catalan Water Agency said the Besòs river at Santa Coloma de Gramenet had risen above its danger level. All entrances to the Besòs river park were closed because of the risk of overflow.
AEMET spokesperson Rubén del Campo forecast more showers and storms, some bringing hail. Temperatures were expected to fall from Tuesday, bringing an unseasonably cool spell before recovering by the weekend. The Mediterranean coast was set to warm, and the Guadalquivir valley could reach 32°C. On September 30, AEMET had warned of very heavy, prolonged rain from Thursday through October 5. Castellón, Valencia, northern Alicante and nearby areas could receive more than 150 l/m² in less than six hours, raising the risk of flash floods.
Showers were likely across most of Spain on Tuesday, especially in the north and central regions. Extremadura, western Castilla-La Mancha and the Sistema Central were forecast to see heavy rain and hail. Unsettled weather was also expected in the Balearic and Canary Islands, with scattered showers and calima in the Canaries.
La Razón reported that Catalan Civil Protection confirmed two deaths. One person died in Tordera after a campsite wall collapsed; another drowned in the parking lot of their home in Montmeló/Montornès del Vallès. A person was also reported missing in Pineda de Mar, possibly swept into a river channel.
By Wednesday, the cool spell was expected to deepen, particularly in northern Spain and the Canary Islands. The heaviest rain was forecast to shift north, bringing further storms and hail to the Cantabrian coast, the northeast and the Balearic Islands. The west and south were expected to clear, although rain remained in the forecast for the north of the Canary Islands.
More stable, anticyclonic weather was expected from Thursday. Strong showers could persist in the far north, Catalonia and the Balearic Islands, but rain was forecast to ease by the weekend. Temperatures were expected to recover, though they would remain cool for October.
Rubén del Campo also pointed to record warmth in the Mediterranean. At the end of September, the Balearic Sea was above 26°C, a record for that time of year. The warmth increased evaporation and humidity, fuelling the convective storms. Classic triggers such as a strong 'dana' or trough were missing, but meteorological sources said the DANA system had formed west of Portugal. The warm Mediterranean loaded the air with moisture and energy, intensifying the storms and bringing hail and lightning.
Sunday set an October record for lightning, with 83,230 strikes across Spain. The storms’ scale and frequency raised the question of whether Spain was seeing something like tropical cyclogenesis. Juan José González Alemán of AEMET said the extreme event in Catalonia was “consistent with a process of tropical cyclogenesis, that is, a genuine attempt at tropical cyclone formation from a cluster of very strong storms.” If confirmed, this would be a first for the Mediterranean and could affect climate science in the region.
Experts including Ángel Rivera and climatologist Samuel Biener said the event needs further study. They pointed to similarities with tropical systems and the possible role of mesoscale convective vortices as seeds for new cyclones. The Catalan branch of AEMET urged caution while acknowledging that the event was unusual. It also noted that climate change is warming Mediterranean waters and intensifying rainfall extremes.
The worst flooding may be over, but last week’s weather exposed risks linked to record sea temperatures and persistent atmospheric instability.
