A westerly and very variable flow prevails over the whole area.
For Berck sternes :
No gale warning.
For the night from Wednesday to Thursday WNW force 3 in the early part of the night becoming W force 2. Gusts reaching 15 knots in the early part of the night.
Smooth to slight sea becoming slight in the middle of the night. Low, short swell from W then from N in the middle of the night. Excellent visibility. Daytime of Thursday 20 august : The atmosphere will remain unstable.
Skies changeable to very cloudy. Light showers all day. In the evening, cloudy spells, sometimes dense.
Possibility of showers W force 3 in the morning becoming WNW force 4 in the middle of the day. Slight sea. Low from N. Excellent visibility.