[VOA]

Hello Professional Engineer,
Please help out the folks who just struggled to pass college physics (etc.) what
accounts for the image.

Is the sun-lit rectangle of land behind the car there because the moisture (overcast)
has been pushed ahead of the car?

Please bear with us...this is magic to some of us non-physics/engineering types.

[null and void]

I think it's dust jarred loose by the shock wave.

Let's see what PE says...

[Professional Engineer]

IIRC the shock wave was back lit by the setting sun. The apparent change in color is probably due to the slight change in angle in the airflow on each side of the wave itself. It would refract light just slightly differently.