A red alert has been issued for torrential rain across parts of Valencia, Castellon and Tarragona amid fears of flash flooding.
Aemet’s most serious warning, classified as an ‘extraordinary danger’, will take effect at 6pm on Thursday, October 1.
The state weather agency forecasts that the worst-hit areas could receive 90 litres of rain per square metre in just one hour and up to 250 litres within 12 hours.
The warnings cover the northern and southern coasts of Castellon, the northern and southern coasts of Valencia and the southern Tarragona coastline.
In Castellon, the red alert is expected to remain active until 11.59am on Friday. The most severe warnings in Valencia are initially scheduled to remain in place until 1.59am.
Regional emergency officials have warned that accumulations could reach 300 litres per square metre around Castellon Airport.
Emergency alerts sent to phones
The Valencian Government sent ES-Alert emergency warnings to mobile phones across affected parts of Valencia and Castellon on Thursday morning.
Residents have been instructed to avoid unnecessary journeys, stay away from rivers and ravines and obey all road closures.
Anyone who sees water beginning to rise should move to an upper floor.
Orange warnings, representing an ‘important danger”’ will begin from 2pm in surrounding areas before the red alerts are activated four hours later.
The northern Alicante coast, inland Valencia and southern inland Castellon are among the areas placed under orange warnings.
Authorities are particularly concerned about sudden rises in normally dry riverbeds and ravines, where fast-moving floodwater can appear with little warning.
Schools closed
More than 50 municipalities have suspended classes, while the University of Valencia has moved teaching online from Thursday afternoon.
Valencia city ordered schools to close from 3pm on Thursday and remain shut on Friday.
Numerous other municipalities, including Sagunto, Torrent, Paiporta, Gandia, Catarroja, Aldaia and Chiva, have also cancelled lessons.
Public parks, beaches, cemeteries, sports facilities and outdoor activities have been closed or suspended in several areas.
Ford’s Almussafes factory has cancelled industrial shifts, while businesses and public institutions are activating emergency plans.
‘Catastrophic’ impacts possible
Under Aemet’s warning system, a red alert means vulnerable people and property in exposed areas could suffer ‘very serious or catastrophic’ impacts.
The danger is not limited to the total amount of rain. Slow-moving or stationary thunderstorms could release enormous volumes of water over the same location within a short period.
The Spanish Government’s representative in Valencia, Pilar Bernabe, said the episode was not technically a DANA or gota fria, but involved atmospheric instability intensified by unusually warm Mediterranean waters.
The southern Tarragona coast is also under a red warning, with Aemet forecasting 90 litres per square metre in one hour and as much as 250 litres in 12 hours.
Catalan forecasters have placed nine districts under very high risk, including Montsia, Baix Ebre, Terra Alta, Baix Camp and Tarragones.
What residents should do
Authorities have urged people in affected areas not to travel unless strictly necessary.
Drivers should never attempt to cross a flooded road, bridge or underpass, even if the water appears shallow. Vehicles can be swept away by a relatively small depth of fast-moving water.
People should stay away from beaches, rivers, ravines and low-lying areas, move vehicles from flood-prone locations where it is safe to do so and monitor official Aemet, regional emergency and 112 updates.
In an immediate emergency, call 112.
