AIR MAIL
Where today’s air came from
The air arriving over Manhattan Beach about 5,000 feet above the ground was over the Pacific off California three days ago, and over the Great Basin a day ago, about 1,190 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 southern California; at 10,000 feet, from the Pacific off California. Air off the water carries moisture, which is why it feels humid. Traced back 72 hours through NOAA’s hourly RAP analyses, nine paths at each of three heights.