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

MOLINE, Ill. — A new study published by the American Meteorological Society has shed light on a puzzling phenomenon: The United States has not logged an EF5 tornado, the most violent category ...

Tornadoes are classified on the Enhanced Fujita scale, which ranges from EF0 to EF5. Originally created by famed tornado researcher Ted Fujita, the scale takes into account estimated wind speeds ...