7 Near gale Sea heaps up and white foam from breaking waves begins to be blown in streaks along the direction of the wind. Whole trees in motion, inconvenient to walk against the wind. The foam is blown in well marked streaks along the direction of the wind Twigs break from trees, difficult to walk. 9 Strong gale High waves. Dense streaks of foam along the direction of the wind.
Crests of waves begin to topple, tumble and roll over.
Spray may affect visibility. Slight structural damage occurs, chimney pots and slates removed. 10 Storm Very high waves with long over hanging crests. The resulting foam in great patches is blown in dense white streaks along the direction of the wind. On the whole, the surface of the sea takes on a white appearance.