Dozens of tornadoes reported in the South National Weather Service Posted at 2:15 PM, Mar 17, 2021 and last updated 2021-03-17 23:23:21-04 BIRMINGHAM, Ala. (AP) â Hundreds of schools, COVID-19 vaccination clinics, businesses and more closed down across the Deep South as forecasters warned of waves of severe weather, including massive tornadoes, downpours and hail the size of tennis balls. The National Weather Service reported nearly two dozen twisters on Wednesday. âA significant tornado outbreak is expected with numerous strong and a few long-track, potentially violent tornadoes,â wrote the NWS. Forecasters say at least two waves of storms are likely, and the worst might not hit until a cold front passes overnight.