Squall. On Saturday, February 19, 2022, Norfolk Southern Corp 20K (63rd Street Yard/Chicago, IL-Croxton, NJ) crossed the Juniata River in Mount Union, Pennsylvania with NS 4458 (AC44C6M) leading. Not 20 minutes prior, the air was cold, but the sun was out. Suddenly and dramatically, visibility reduced as a snow squall approached. The train passed just as the brief storm was beginning to ease.