That horrible combination of rain that is not quite snow...but soon will be.
Basically, it's airborne precipitation that fluctuates mid-drop, and can't seem to make up its mind whether it's rain...or snow...
(This word was created by Stephanie Tyler, of Eaton Township, Ohio.)

A snow rain mix.

Verb: When it rains and snows at the same time.

Snaining is when it is snowing but also raining at the same time