Each tornado touched down in Saturday's early hours, with the last and smallest observed at 5:14 a.m. An EF-1 ...

The Enhanced Fujita Scale provides an estimated range of a tornado's wind speeds, based on the tornado's damage.

One question you may ask yourself is how tornadoes are measured? It's with the Enhanced Fujita (EF) scale which is gives a ...

A dangerous tornado outbreak featuring the potential for "multiple violent" tornadoes threatens much of the Deep South ...

The National Weather Service on Saturday confirmed at least three EF-2 tornadoes touched down in southern Indiana.

The National Weather Service has confirmed at least four tornado touchdowns occurred in the Chicago area during a severe weather outbreak Friday.

Researches found little evidence that tornadoes were getting weaker. Instead, it appears that a subjective tornado grading system is to blame.

Large and destructive tornadoes are carving paths of destruction across the South for the second day in a row.

A quirky aspect of the way we measure twisters helps explain why there hasn't been a top-tier-rated tornado in 12 years.