The districts of Viana do Castelo, Braga, Porto, Aveiro, Coimbra, Leiria and Lisbon will be under an orange warning between 12pm today and midnight on Saturday.

The institute predicts "waves from the west/northwest measuring five to six metres, potentially reaching ten metres in maximum height."

These seven districts then move to a yellow warning, also due to the forecast of strong sea agitation, wind and precipitation.

The districts of Beja, Bragança, Castelo Branco, Faro, Guarda, Setúbal, Vila Real and Viseu will also be under a yellow warning from 12pm today, some due to rough seas, others due to the forecast of periods of rain, sometimes heavy.

The National Maritime Authority (AMN) and the Navy warned on Thursday of “a considerable worsening” of weather conditions and rough seas in the north of mainland Portugal, from midnight on Friday until midday on Saturday.

For Saturday, the IPMA informs that all districts on the Portuguese coast will be under a yellow warning due to the forecast of rough seas.

Therefore, Viana do Castelo, Braga, Porto, Aveiro, Coimbra, Leiria, Santarém, Lisbon, Setúbal, Beja and Faro will remain under yellow warning until midnight on Sunday.

For today, the IPMA predicts periods of rain, sometimes heavy in the north and centre, gradually turning into showers. Strong winds are still forecast on the west coast and in the highlands, in addition to strong sea agitation.

IPMA also predicts the possibility of thunderstorms in the north and central regions from the afternoon onwards.

It also predicts a small rise in the minimum temperature and a small fall in the maximum temperature.