AtlanticFlamethrower

Hi, I've just been walking outside. Beautiful clear blue skies, and the few airplanes there are in it are like comets, shooting across the sky with short white contrails behind them. This is different to yesterday. Sunday the jets were leaving persistent contrails. Sunday was a pretty good day like today. What is the difference that explains the short contrails we have today and the ones that covered the entire sky yesterday?

The difference may have something to do with temperature and humidity.

What charts can I look at which show this so I can predict which days will have short and long contrails ... and by extension, by looking at contrails alone be able to know what the temperature/humidity is like at certain heights in the atmosphere.

You can track the heights of the contrails using flightradar.

http://www.flightradar24.com/

Any help answering this question and links appreciated.