AEMET's red warning begins at 18:00 on Thursday across the coast and northern interior of Castellón, as well as the coasts of Valencia and Tarragona. It is expected to remain in place through Friday. More than 250 litres of rain per square metre could fall in Tarragona within 12 hours on Friday, with the heaviest burst bringing 90 litres in one hour.
The province has already seen flooded roads as the storm system crossed Catalonia. The intensity and volume of rain pose a direct flood risk and make driving dangerous on affected roads. Emergency services have urged people in Tarragona, Castellón and Valencia to take extra care.
Protecció Civil Generalitat sent Es-Alert flood warnings to several Tarragona comarcas, including Garraf, Alt and Baix Penedès, Alt Camp, Tarragonès and Baix Camp, after earlier alerts in Montsià, Baix Ebre and Ribera d’Ebre.
The warning stretches well beyond the eastern coast. It covers southern Alicante, the Region of Murcia and the area around the Almería and Jaén border. Castilla-La Mancha, the Community of Madrid, southern Castilla y León and parts of Aragón also face storm-related risks.
Repeated alerts had already swept across Catalonia and the Valencian Community on Thursday. The warnings reached red level in the afternoon as the rain grew much heavier. Water covered roads in Tarragona and disrupted traffic. Regional Catalan authorities confirmed local flooding and traffic problems as storms strengthened over the Mediterranean.
Meteocat has identified Terres de l'Ebre, Camp de Tarragona, Penedès and Garraf as risk areas. Some downpours could exceed 40 litres per square metre in 30 minutes, with thunderstorms and local hail.
Storms are becoming more organised over the Mediterranean. Tarragona is at the centre of the forecast, while Castellón and Valencia also face further storm activity. Southern Alicante and Murcia remain on the risk map.
Flooding is the basic concern. Catalan authorities tie the red alert to both rainfall intensity and the total amount expected. Sudden floods, road closures and movement restrictions could begin in the first hours of the warning.
People in inland regions may also face dangerous conditions, though the highest figures are forecast for Tarragona. The mix of coastal and inland alerts extends the risk well beyond the areas hit on Thursday.
The Friday forecast gives no end time for the storm. Tarragona could receive more than 250 litres per square metre in 12 hours, with up to 90 litres possible in one hour. Those figures explain why the province has the highest warning level.
Regional authorities say the red alert reflects the rain's intensity and expected accumulation. Roads may close quickly, making travel difficult.
Residents should take the warnings seriously from early morning and avoid unnecessary travel near flooded roads. Friday is expected to bring the most dangerous conditions in Tarragona, while other parts of Spain also face storm risks.
