AIR MAIL
Where today’s air came from
The air arriving over Maurice River about 5,000 feet above the ground was over the western Atlantic three days ago, and over the Great Lakes a day ago, about 1,290 miles back along its path. The nine paths traced from around the city fan out, so treat that as a best guess. Near the ground the air came from the Maritimes; 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.