Why does the Lorenz model show deterministic chaos in turbulent flow?

[Nusc]

It's not clear to me why the Lorenz model shows us that the apparent unpredictability of turbulent fluid dynamics is deterministic.

Can anyone explain?

 

[Eynstone]

The Lorenz model uses deterministic equations & is, therefore, deterministic. It's the differential equations which show chaotic behaviour.You might want to read more :
http://en.wikipedia.org/wiki/Lorenz_attractor