Haart,
I have doubts that the footage shown was taken over Syria yesterday, or a day before. Russian TV have tonns of such footage to select the one with a good quality and put on air.
Concerning the clouds... Yes, EO/IR sensors do not work through them, but a conventional radar is enough for target acquisition. I assume that a stand-alone vehicle is a too hard target for it, but for bombing "dimensioned" targets like long columns of trucks or an oil plant it should work.