Howling sound at start up

Recently with the temps getting colder (below 50) Ive noticed a howling sound that lasts until my jeep is warmed up. Running this morning I had the sound at idle but then it dissappeared when I hit the gas. As I continued driving the sound stopped at idle and then I heard it when accelerating until it completely stopped when fully warmed up.

I ran it without the serp belt to confirm its a belt driven accessory but I can't figure out where the noise is coming from. The sound seems to be coming more from the passenger side leading me to think maybe alt, ac pulley, fan clutch, possibly the water pump. The alt and a/c turn freely by hand with no noise. Tensioners all turn freely as well. The water pump which is new as of the summer turns freely, makes a very faint sound and has no shaft wobble or leakage. This leads me to the fan clutch. Are there bearings that can go bad on the fan clutch? Anything thing else to consider before I start throwing parts at it blindly?

The fan clutch has no bearings. Start with increasing the fan belt tension. When the noise happens, stop the engine and spray lots of WD-40 into the alternator, if the noise goes away ........

I had the same problem a few years ago with my D.D.-- noise 'til it warms up and quieter as the temps increased.
P.S. pump turned out to be the culprit, even though the sound really seemed to be coming from the passenger side. Check the pulley/pump for lateral play with the belt removed to verify......... wish I'd done that before it ate a pump on the way to work!

I used a mechanics stethoscope on all belt driven accesories today and found the alternator making a much louder sound than the rest. It seemed to quiet down quite a bit when warm. Hopefully this is the problem as I just ordered a new one.