TurboTristar From , joined Dec 1969, posts, RR: Posted (13 years 10 months 3 weeks 2 days 17 hours ago) and read 1008 times:
I have noticed for several years, that is seems contrails appear more over St. Louis (my home), much more in the fall than in the spring or summer. Why would this be? Different weather patterns, or different flight directions? I would hardly see any in the spring or summer, but now there are contrails everywhere!
Hmmmm... From Canada, joined May 1999, 2104 posts, RR: 5
Reply 1, posted (13 years 10 months 3 weeks 2 days 16 hours ago) and read 991 times:
Well, one of the factors that determine size of contrails is the moisture content of the air up there. More moisture will allow for a larger contrail. Why there would be more moisture in the fall than in the spring, over St. Louis, I don't know.
An optimist robs himself of the joy of being pleasantly surprised
Astrojet From Germany, joined Aug 2000, 565 posts, RR: 2
Reply 2, posted (13 years 10 months 3 weeks 2 days 9 hours ago) and read 965 times:
Here in Ibiza (Spain) we have very few contrails in the summer time, but in the winter we have a lot.
I agree with Hmmmm... that moisture is the most important factor, another one might be temperature.