Yesterday was as remarkable in its way as the day before in its generic beauty. Delicate Strands and fibrous blobs of Cirrus in interesting shapes floated by overhead with nary a contrail to contaminate those scenes. While our little part of the sky above Catalina, Arizona, is a low contrail impacted zone of the sky, yesterday seemed exceptional. It mgiht have been because, and since I am guessing here, will not check it out, those wonderful clouds and that moist layer they were embedded in was LOWER or HIGHER than usual, and the flight levels that the jets were flying in remained very dry so that they don’t persist. Its the ambient humidity up there that makes them various lengths. If its too dry, there is only that bit right behind the jet–recall Appleman (1951) and the Appleman diagram.
Also, the wind direction at flight levels helped; due west generally keeps those contrails packing airways just to the north of us and to the south streaming along beside us, not over us. That always helps.
But, I didn’t really see much off to the north, where there are usually a half dozen or so on any “Cirrus-ee” day.
Was it because it was New Year’s Day and air traffic is unusually low because no one wants to travel because they wouldn’t be able to watch the Rose Parade and various football bowl games? Don’t know, but maybe.
I have given you a LOT of things to think about, and while you’re doing that, I will post some evidence, contrail-less Cirrus skies. You won’t find this kind of day we had yesterday along the Atlantic Seaboard on any day with Cirrus with all the jet activity.
The weather ahead?
There isn’t any. Well, any worth mentioning right now. Gotta get through this week or two dry spell somehow…
Will dredge up some January climo tomorrow or the next day.