Contrails

[Bob Cook]

bad piston rings can cause "blue" contrails" .
Lots of contrails around OSH during showtime.....

Interesting to note that when the moisture is up (RH) is when you see contrails... usually denotes a wx system moving in (as in tropical air mass). Sometime you can see the contrails starting and that " transitional zone" will move eastward over a period of time. It is just a bunch of frozen ice particles (moisture) reflecting in the sun. If the moisture (RH) is less (as in artic air mass with low humidity the crystals sublimate and no crystals will be seen.

Great predictor (one day or so) to detect a change in the wx locally.

think i have it right...

bob