A cat's paw is the imprint that a light breeze that ruffles small areas of a water surface. When generated by light wind in open water, a nautical name for them is cat's paw waves, since they may resemble paw prints (Figure 10.20). Light breezes which stir up such small ripples are also sometimes referred to as cat's paws. On the open ocean, much larger ocean surface waves (seas and swells) may result from coalescence of smaller wind-caused ripple-waves.
A squall is a sudden violent gust of wind or a localized storm. A squall line is a line of thunderstorms that can form along or ahead of a cold front. It contains heavy precipitation, hail, frequent lightning, strong straight-line winds, and possibly tornadoes and waterspouts. At sea, a squall is used to describe a relatively rapid change in weather from calm or mild weather to sudden strong winds and intense precipitation, usually associated with passing a cold front.