High over lake Michigan

[charlie2]

I have flown the PHL to MSP trip numerous times over the past few months and have noticed that there is a short period of moderate turbulence pretty much over the middle of lake Michigan. Today the whole flight was smooth except for the middle of the lake at 380. I have noticed this almost every flight. The length of the turbulence is only a few seconds and then it goes back to smooth. Is there some meterological thing here?

 

[avbug]

Think about the location of the jetstream as you passed that location.

 

[Andy Neill]

....and the chemtrail dump which in that area.