AIR MAIL
Where today’s air came from
The air arriving over Rockwood about 5,000 feet above the ground was over the southern Rockies three days ago, and over the southern Plains a day ago, about 990 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 Mississippi Valley; at 10,000 feet, from the southern Rockies. Traced back 72 hours through NOAA’s hourly RAP analyses, nine paths at each of three heights.