Worsening of the weather this weekend.
12 metre waves possible The Journal reports that the National Maritime Authority have issued an alert, which provides for "a worsening of the weather and oceanographic conditions in the Madeira archipelago, between Saturday morning, November 17th, and Sunday afternoon, November 18th." Waves will come from Northwest quadrant, with a height that can reach 7 metres "or in the worst case, a maximum height of 12 metres". The wind will reach speeds of 36 km/h with gusts above 60 km/h." The Authority recommends that care is exercised especially by owners of moored vessels, and that people avoid walkways by the sea, especially on piers and beaches. They recommend that coastal areas are avoided, especially in areas with heavy waves and caution that the sea may be dangerous in apparently safe areas.
See here: https://madeiraislanddirect.com/blog/2018/11/worsening-of-the-weather-this-weekend/