AIR MAIL
Where today’s air came from
The air arriving over Wells about 5,000 feet above the ground was over the northern Rockies three days ago, and over the Great Lakes a day ago, about 1,710 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 a point about 420 miles to the southwest; at 10,000 feet, from the Great Basin. Traced back 72 hours through NOAA’s hourly RAP analyses, nine paths at each of three heights.