The alert will be in effect in Viana do Castelo, Braga, Porto, Aveiro, Coimbra, Leiria and Lisbon between 6am and 9pm on Tuesday.


The warning is the third highest on a scale of four, with the Met Office predicting waves that could reach up to ten metres along the coastline of the afore-mentioned districts.


The southern districts of Beja, Setubal and Faro have been placed under a Yellow alert for tomorrow, with waves there expected to reach up to 5 metres.