What is a wedge tornado?

If you watch FOX Weather coverage of severe weather events, you may hear the term "wedge" when describing a tornado.

"‘Wedge’ is informal storm observers' slang for a tornado which looks wider than the distance from the ground to ambient cloud base," the National Weather Service says

While it may look scary, it has no scientific meaning other than appearance. 

Many notable "wedge" tornadoes have also been violent, producing EF-4 to EF-5 damage.

"A tornado's size does not necessarily indicate anything about its strength," the National Weather Service says.