28–33 knots. Sea heaps up and white foam from breaking waves begins to be blown in streaks.
Gale force winds can cause structural damage to roofing and siding and create life-threatening conditions for mariners. Weather Spotter's Field Guide - Non-supercell Tornadoes gail force
34–40 knots. Moderately high waves of greater length; edges of crests break into spindrift. 28–33 knots
Winds are categorized based on their intensity and the observed conditions they cause: gail force