I am getting a negative value of Velocity in my Flow Simulation analysis. It is not much, something like - 0.5 m/s

This made me puzzled: How can a velocity of a wind have a negative value???

I know that pressure can have a negative and positive value. Positive value of wind will act like a compressional force towards the object. And negative value of pressure will act like a suction force.

But velocity can only take positive value. How can a velocity take a negative value?

Did I just miss some of the physics classes, or is this just Flow Simulation error?

Thank you for the replies.