What does "IC" signify when included in a TAF?

The inclusion of "IC" in a TAF signifies ice clouds. Ice clouds refer to clouds composed primarily of ice crystals, which typically occur at higher altitudes where temperatures are low enough that water vapor freezes. This is essential information for pilots and meteorologists as ice clouds can indicate the potential for light to moderate turbulence and icing conditions, both of which are critical for flight operation safety.

When looking at the other options, although "Ice conditions" seems somewhat related, it does not accurately reflect the specific terminology used in TAF reports. Similarly, "Intermittent conditions" refers to varying weather that can occur sporadically, which does not pertain directly to the "IC" abbreviation. Lastly, "Immediate change" suggests a rapid alteration in weather, which is not what "IC" conveys in the context of terminal aerodrome forecasts. Thus, "IC" specifically designates ice clouds, making that the most accurate choice.