Colder temperatures than clear ice below freezing in stratus or fog from -10-degrees to -20-degrees C. Forms when aircraft surface temperature is below freezing and then flies through supercooled water droplets.
(aircraft surface temperature; is; below freezing) (aircraft surface temperature; flies; through supercooled water droplets; T:then)
aircraft surface temperature aircraft surface temperature
is flies
below freezing
through supercooled water droplets T:then