AIR MAIL
Where today’s air came from
The air arriving over Pine Lake about 5,000 feet above the ground was over Texas three days ago, and over the southern Rockies a day ago, about 1,210 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 Texas; 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.