The alert will be in effect between 15:00 on Thursday and 12:00 on Friday, with northwest waves of 4 to 4.5 metres.

According to the Portuguese Institute of the Sea and the Atmosphere (IPMA), nine districts will be under yellow warning on Thursday and Friday due to “maritime agitation”, with northwest waves expected to reach 4 to 4.5 metres.

The alert in the districts of Porto, Aveiro, Faro, Setúbal, Viana do Castelo, Lisbon, Leiria, Beja, and Braga will be in effect between 15:00 on Thursday and 12:00 on Friday.

The yellow warning, the least serious, is issued by the IPMA whenever there is a risk situation for certain activities dependent on weather conditions.