Even at temperatures significantly less than 0 C. ice sublimes to be readily observable, as you also point out.

The combined apparent visual magnitude of the two stars is 2.68, making it readily observable with the naked eye.

This intelligence is readily observable in the wild.

As a result both abuse and early marriage may be associated with factors which are not readily observable.

Given that the observer is aware of the tasks set by the teacher this too should be readily observable category.

But, as the researchers caution, these are the only attributes that are readily observable in the data.

This may occur because peoples' own internal states are more readily observable and available to them than those of others.

All this - and I could go on at great length - is readily observable.

A readily observable location can also permit so-called passive security from passers-by.