Dirty Rain Friday Afternoon

Anyone else notice that their car was dirty after it rained Friday afternoon?  It was almost like it rained dirt and dust.  Well..it kind of did.

In order for rain droplets to form, water vapor (gas in the atmosphere) must have something for it to condense on to.  These 'condensation nuclei' are particles in the atmosphere, such as dust or dirt, that act as a focal point for water vapor to collect on and become water droplets - gas state into a liquid state.  Sometimes after a light rain you may notice the rain drops left behind a little dirt, but many cars Friday afternoon became quite dirty following the light rain that fell over northern Illinois.

Winds increased quite a bit Friday afternoon and early evening.  The quick increase in wind caused a lot of the dust and dirt from nearby fields, because of how dry it has been, to become suspended in the atmosphere.  As the rain came down the dust particles 'collected' on the rain drops as they fell through the air.  Once the rain hit ground and vehicles it evaporated, leaving behind the dirt and dust you saw on your car.