Means a flash flood is possible in the area, stay alert. Means a flash flood is imminent, take immediate action. A storm that forms outside the tropics, sometimes as a tropical storm or hurricane changes. See table below for differences between extratropical and tropical cyclones. The low pressure center of a tropical cyclone.
Winds are normally calm and sometimes the sky clears.
The ring of thunderstorms that surrounds a storm's eye. The heaviest rain, strongest winds, and worst turbulence are normally in the eye wall. A tropical cyclone with winds of 74 mph or more. Normally applied to such storms in the Atlantic Basin and the Pacific Ocean east of the International Date Line. A measure of speed.