The Portuguese Institute of the Sea and Atmosphere (IPMA) indicated that the districts of Viseu, Vila Real and Aveiro will be under an orange warning between 06:00 and 12:00 on Thursday and the districts of Porto, Viana do Castelo and Braga between 18:00 on Wednesday and 09:00 on Thursday.

These six districts are already under a yellow warning today and Wednesday due to persistent and sometimes heavy rain.

Due to the heavy rain, the IPMA has also placed the districts of Bragança, Guarda and Coimbra under yellow warning between 03:00 and 12:00 on Thursday.

The orange warning is issued by the IPMA whenever there is a "meteorological situation of moderate to high risk" and the yellow warning when there is a risk situation for certain activities dependent on the meteorological situation.

On Monday, in a statement, the IPMA indicated that the situation is due to the "transport of a mass of tropical air, with a very high water vapour content, in the joint circulation of an anticyclone located south of the Azores and a depression region in the North Atlantic".

According to the IPMA, periods of persistent rain are expected from today in the North and Centre regions and that it will sometimes be heavy on Wednesday and Thursday, especially on the coast north of Cabo Mondego and mountainous regions.

In the southern region, precipitation will generally be light, although unlikely in the interior of Baixo Alentejo and Sotavento Algarve, and may be temporarily moderate during the morning of Thursday.

Following the IPMA forecast, the National Emergency and Civil Protection Authority (ANEPC) warned the population on Monday about the risk of flooding, landslides, landslides and falling structures and trees.

ANEPC recommended the "adoption of appropriate behaviour", such as unblocking rainwater drainage systems, correctly securing loose structures, such as scaffolding and panels, and defensive driving on the roads, reducing speed and taking "special care when driving and staying near wooded areas".

In light of the forecasts, ANEPC warned of the possibility of flooding in urban areas due to the accumulation of rainwater due to obstruction of drainage systems and flooding "increased by the overflow of the beds of some watercourses, rivers and streams", as well as the detachment of mobile or poorly secured structures and the dragging of loose objects onto the roads.

In particular, in areas recently hit by forest fires, which burned vegetation and covered the ground with ash, ANEPC highlighted the risk of landslides, collapses and contamination of drinking water sources.