In a statement, the authorities explained that the forecast for the state of the sea points to a "considerable worsening" of weather conditions and "sea agitation" from Wednesday until midnight on Thursday, October 10.

According to the note, the sea swell will be characterised by waves coming from the west, "with a significant height that could reach seven metres and a maximum height of 13 metres, with an average period varying between nine and 21 seconds".

According to the Navy and the National Maritime Authority, winds are expected from the southwest quadrant, "with an average intensity of up to 75km/h [kilometres/hour] and gusts of up to 135km/h", in addition to the possibility of precipitation between 0.3 and 25 mm/6h in some regions.

Therefore, the authorities warn the entire maritime community and the general population to take precautions, both when preparing to go to sea and when at sea or in coastal areas.

The Navy and the National Maritime Authority call for increased mooring and for close surveillance of moored and anchored vessels.

The authorities also urge the population to avoid walking along the sea or in areas exposed to rough seas, such as the protective jetties of ports, cliffs or beaches, to avoid being surprised by a wave.

They also advise against recreational fishing, especially near cliffs and cliff areas "frequently hit by breaking waves, always bearing in mind that in these conditions the sea can easily reach seemingly safe areas".

The districts of Viana do Castelo and Braga are under an orange warning from today due to the forecast of rain, wind and rough seas, the day on which the effects of Storm Kirk will begin to be felt.

According to the Portuguese Institute of the Sea and Atmosphere (IPMA), Storm Kirk is expected to move northwest of the Iberian Peninsula, after passing north of the Azores archipelago, and approach the mainland on Wednesday morning, with worsening weather conditions this afternoon.

Due to the worsening weather conditions, the IPMA has placed the districts of Braga and Viana do Castelo under an orange warning due to the forecast of persistent, sometimes heavy rain, turning into showers that may be accompanied by thunderstorms from 9:00 pm today until 9:00 am on Wednesday.

Braga and Viana do Castelo, as well as the district of Porto, are also under an orange warning due to southwesterly winds with gusts of 75 kilometres per hour (km/h), reaching up to 95 km/h on the coast and up to 110 km/h in the highlands between 3:00 am and 9:00 am on Wednesday.

The IPMA has also issued an orange warning for the entire Portuguese coast due to rough seas, with waves from the west expected to be five to six metres high, with a maximum height of 12 metres from 9:00 am on Wednesday until midnight on Thursday.