What are those funny curves?

How are they made?

Why are two values the concurrent measurement after one hour??

The measurements were actually recorded from our weather station on October 30th. The locations are modified from the graph direction...and repeated for one hour.

 

What could happen? What could be behind it?

 

Are these values consequences of a strange Natural event or is there something much more powerful hiding behind them??

 

Solve the riddle!!