AIR MAIL
Where today’s air came from
The air arriving over Franklin about 5,000 feet above the ground was over the Ozarks three days ago, and over the southern Plains a day ago, about 1,070 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 Ohio Valley; at 10,000 feet, from the northern Plains. Traced back 72 hours through NOAA’s hourly RAP analyses, nine paths at each of three heights.