I woke up today in a California hotel room and looked out the window. Billowing majestically over the mountains were waves of flat striated "clouds" of various width, interspersed with some smaller more clearly defined "persistent contrails". I am not near a major airport and the humidity is low. But according to NASA:
The temperature and humidity of the air affects how long contrails last. When air is dry, contrails last just seconds or minutes. But when the air is humid, as was the case here, contrails can be long-lived and spread outward until they become difficult to distinguish from naturally occurring cirrus clouds.
I checked weather.com and apparently the humidity here is 38%. Doesn't seem high to me.
Meanwhile the place I live at, a humid city in Latin America, has an international airport just 10 minutes from me and I've yet to see a day like this (humidity there is almost 70%). Not one. But I visit California for one day and I see this.
So maybe I'm just crazy, but unless I see a better explanation it looks like they are turning some spray on in certain cities, countries or states selectively. Or does jet fuel just work differently in the Northern Hemisphere? I'd love for one of the science loving normies who lurk here to chyme in with a definitive answer.
Otherwise, it looks like here in California, we are getting chemtrails for Christmas! Perhaps Santa's reindeer are flying those planes and were informed we'd all been naughty this year. You all let me know!
Yes, they are dispersed at higher elevation but would I have any reason to believe that a region of consistently low humidity at ground level would have consistently higher humidity at high altitude?
That makes no sense to me. I have never one day seen such a sky in this more humid city, over the course of a full year. Meanwhile every time I visit California there they are. That tells me all I need to know.