48–55 knots. Very high waves with long overhanging crests; the sea surface takes on a white appearance. Safety and Preparation Guide
41–47 knots. High waves; dense streaks of foam along the direction of the wind; sea begins to roll. gail force
28–33 knots. Sea heaps up and white foam from breaking waves begins to be blown in streaks. 48–55 knots
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