Most aviation meteorology books with a section on icing will tell you about supercooled water droplets - ie those existing below 0 degrees C which can be found in temperatures as low as -40 degrees C, normally in cloud with lots of vertical movement.
However, it requires the absence of appropriate freezing nuclei in the atmosphere for the water to freeze onto.
I remember the "supercooled water droplets" and "condensation nuclei" questions but have never had any experiences related to it.
It was wayyy back in my head-noodle. I would guess it's pretty hard to find modern day sky that is not packed with condensation nuclei.
I was just searching for weather related reasons this HEMS crash could have happened. I know fast-forming fog could put a pilot in a
situation with no "out."