AIR MAIL
Where today’s air came from
The air arriving over Yankeetown about 5,000 feet above the ground was over the Gulf Coast three days ago, and over the eastern Gulf of Mexico a day ago, about 440 miles back along its path. Most of the nine paths traced from around the city agree. It rose from near the ground on the way. Near the ground the air came from the Tennessee Valley; at 10,000 feet, from the Mississippi Valley. Traced back 72 hours through NOAA’s hourly RAP analyses, nine paths at each of three heights.