at about 4:40pm, Oct. 4, 2000 in Houston, TX.
In checking the winds aloft, the temperatures were too warm for "normal" contrail formation.
FT 3000 6000 9000 12000 18000 24000 30000 34000 39000
HOU 1607 1509+16 1213+13 1213+09 9900-06 9900-16 251431 251841 252253
This was a normal commercial plane taking off from Hobby airport
that I heard off to my right as I was taking the chemplane pics.
