AIR MAIL
Where today’s air came from
The air arriving over Lake Emma about 5,000 feet above the ground was over Texas three days ago, and over the southern Plains a day ago, about 1,350 miles back along its path. Most of the nine paths traced from around the city agree. Near the ground the air came from a point about 540 miles to the southeast; at 10,000 feet, from southern California. It feels humid. Traced back 72 hours through NOAA’s hourly RAP analyses, nine paths at each of three heights.