AIR MAIL
Where today’s air came from
The air arriving over Springville about 5,000 feet above the ground was over the North Atlantic three days ago, and over Quebec a day ago, about 1,460 miles back along its path. It rose from near the ground on the way. Near the ground the air came from the North Atlantic; at 10,000 feet, from the western Atlantic. Traced back 72 hours through NOAA’s hourly RAP analyses and the GFS beyond them, nine paths at each of three heights.