Preliminary reports indicate the weekend’s mega-twister rated an EF-3 on the Enhanced Fujita scale, which equates to winds of 158 mph to 206 mph, and the assessment could rise, depending on what surveyors find. ALTON STRUPP/USA TODAY NETWORK
December tornadoes are uncommon but not unheard of. The explosion of twisters across five Midwest and Southern states over the weekend? That might be unprecedented.…