Large trees begin to sway, noticeably difficult to walk. Foam from waves blown in streaks. Small branches broken from trees, walking in wind is very difficult. Long streaks of foam appear on sea. Slight damage occurs to buildings, shingles are blown off roofs, High waves, crests start to roll over.
Large trees are uprooted, building damage is considerable.
The sea takes on a white appearance. Exceptionally high waves, visibility affected. Storm waves at sea. Air is filled with spray and foam. Small craft advisories are usually issued when force 6 is reached.