Potentially record-breaking cold headed for the deep south.
Expect well below average temperatures across the Plains and Midwest.
“Following in the footsteps of the record-setting cool air mass in mid-July, a second blast of air with polar origins will invade the eastern U.S. to close July,” says the Washington Post. “This taste of September…should produce temperatures 10-20 degrees below normal across a large swath of the eastern U.S. by early Tuesday.”