HUNTSVILLE, Ala. — We often see tornadoes develop from hurricanes when they make landfall, but what is the reasoning behind it? The answer is simple: friction.
When a hurricane makes landfall, the winds near the surface slow down ad the upper-level winds keep their momentum, or speed. This change in wind speed is called shear. Keep in mind for tornadic development you need shear, lift, instability, and moisture.
Shear often leads to a column of rotating air that typically generates a tornado. Tornadoes that are spawned by hurricanes typically happen in quadrant 1, also known as the northeast quadrant or right-front quadrant and they usually form within the first 12 hours after the tropical system makes landfall.
Tornadoes that form within hurricanes are often rain-wrapped, making them very hard to see. They're also usually very weak (EF-0 - EF-2) and very brief.