Modern standards qualify the so-called Tri-State Tornado as an F5, a mile-wide funnel with wind speeds greater than 260 mph. Perhaps the best evidence of its destructive handiwork was found on the ...

But the biggest difference ... for various types of buildings and structures. As a result, tornadoes that might have been classified as F5 under the old system could now be assigned an EF4 ...

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

Northwest Florida and the Panhandle are expected to see severe thunderstorms Saturday stemming from what AccuWeather says could be the biggest severe weather and tornado event of the year so far.

"Then the air was filled with 10,000 things. Boards, poles, cans, garments, stoves, whole sides of the little frame houses, in some cases the houses themselves, were picked up and smashed to earth.