Screeching sound after let go of breaks

[Kqpro88]

I got my Z two months ago, it is brand new. So that's why I am wondering if this is a problem.

After it rains outside, I go in my car (pretty cold outside as well, and wet) and start driving. I step on the breaks at a traffic light, and once it comes to a full stop, I hear a little screech sound, it has to be from the breaks.

Then after light turns green, I let go of the break and there is a sound as well, can't really describe it, it's not loud or anything, but it's there.

After driving for 10 mins, when i press the break, or let go of breaks. all sounds go away. they are not there anymore. Is this normal? Is it because it has to warm up?

Thanks for the help.