Contrails and Weather

[Cam]

Me and Barry were out spotting the other day, when we noticed a couple plane's at cruise. Their contrails were short and we commented that there must not be a lot of moisture in the air…is there any truth to that.

And….

If so, does a long contrail mean incoming weather because of the high moisture?

[E-Diddy!]

Yes and No. It does mean that there is alot of moisture in the upper atmosphere, but just because it is there doesn't mean it is going to do anything. True, it has greater potential to do stuff, but something else (convection, for example) has to set it off.

[z740]

the short ones that disapear after a few seconds are called contrails. the long ones that take a while to go away are called CHEMTRAILS. the governments way of trying to control our minds with a special chemical they put into the fuel. just kidding! i'm sure there is an explanation on wikipedia somewhere.

-Chris

[Jerrycobra Boeing]

is wind issue too on how long they last? lol chemtrails is this idea from this group of environmentalists that live under a busy flight path and they are saying that theres a lot of this material on the ground, some kinda chemical

[Foxtrot]

Re:

In general, yes, more moisture at the plane's altitude does mean longer contrails and vice-versa, but it's not necessarily the case, because wind speed can also affect how long the contrail is visible before it burns off (remember it's basically an elongated cloud). But if a contrail is long and stays for a good while, most likely moisture is in plenty at that altitude. It doesn't necessaily mean that there's an oncoming storm system, you can have a lot of moisture at high altitudes and it may be dry down below.