AIR MAIL
Where today’s air came from
The air arriving over Grafton about 5,000 feet above the ground was over the Atlantic off the Carolinas three days ago, and over the western Atlantic a day ago, about 1,190 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 North Atlantic; at 10,000 feet, from the Atlantic off the Carolinas. Traced back 72 hours through NOAA’s hourly RAP analyses and the GFS beyond them, nine paths at each of three heights.