[JAMF]

The FA-18E isn't breaking the sound barrier, but the shockwave creates a very local low pressure area. (The F-15 has a similar low pressure above the wing in that pic) This causes the dew-point to drop, so the water can not stay gaseous and must form liquid droplets, creating the fog.

Doesn't take away the fact that it creates an impressive picture.

This is actually how it looks like when F18 is breaking the sound barrier. So I must disagree with the fact that plane is going slower than speed of sound

Go right ahead.