For Castro Urdiales :
No gale warning.
For the night from Wednesday to Thursday WNW wind force 2 continuing all night. Gusts reaching 8 knots all night.
Slight sea. Low, fairly long swell from NNW. Good visibility becoming good in the middle of the night then good. Daytime of Thursday 20 august : The atmosphere will remain unstable.
Good clear periods alternating with cloudy spells, sometimes dense. Light showers all day. In the evening, cloudy spells, sometimes dense.
Light showers progressively becoming less frequent. WSW force 2 in the morning turning NW force 3 in the middle of the day. Gusts reaching 11 knots in the middle of the day. Slight sea. Low, fairly long swell from NNW then short from N in the evening. Good visibility becoming excellent in the middle of the day then good.