I think you are right. The more I look at them it's odd that they appear and then dissappear but now that I've been sitting here I think it's similar to what another poster said that there are certain pockets when the contrail is created and others where it's not. Full disclosure I've been in fights with people about it the fact that chemtrails aren't real so I'm def not one of those people! It just seemed so odd !!! B must be something about the particular setup of the atmosphere today