The meteorological institute has issued red warnings for extremely rough seas — with swells up to 15 metres — for Porto, Braga and Viana do Castelo overnight from Friday into Saturday, while the broader west coast remains on orange. The three districts will be downgraded to an orange warning between 03:00 and 18:00 on Saturday. Authorities warn of significant risk to maritime operations, coastal infrastructure and public safety; residents and mariners are advised to avoid the shore, follow local advisories and expect disruptions to ferry services and port activity.