Final answer:
The statement is true; a mesocyclone signature in the radial velocity data can indicate the potential for tornado formation, as it signifies atmospheric rotation and wind shear within a supercell thunderstorm.
Step-by-step explanation:
A mesocyclone signature in the radial velocity data can indeed be a precursor to tornado formation, so the statement is True. Mesocyclones are the rotating updrafts within a supercell thunderstorm, which can lead to the formation of tornadoes. Meteorologists look for specific velocity signatures indicative of rotation to identify mesocyclones. A significant indicator of potential tornadic activity is when meteorologists detect strong rotation coupled with a large difference in wind speeds at different altitudes, known as wind shear.
This is because tornadoes are formed due to a change in wind direction and increase in wind speed with height, causing the rotating column of air to align from a horizontal to a vertical orientation, manifesting as a tornado.