Officials warned residents across the South that the effects of a major winter storm were not over, and that driving remained a hazard on roads frozen with slippery ice.

Meteorologists were left speechless Tuesday as record amounts of snow fell along the Gulf Coast. Here’s why it was so snowy.

Heavy snow and ice led to thousands of flight cancellations across the country as the ripple effects of the storm trickled through the airline networks. Airlines cancelled nearly half of all flights into and out of Atlanta on Friday, according to airline tracking company FlightAware. Atlanta is home to the world’s busiest commercial airport.