REALLY loud squeal under hood on drivers side.

Check your surpintine belt,and the idlers,if idlers are good check the power steering pump.

Agreed. Also check harmonic balancer. They are known for making this sort of sound too. Replace it if it's the issue. Also could be timing belt issue. Use caution driving like this till you figure out just what is making the sound. A piece of PVC pipe or hard vacuum hose will give you the ability to listen more closely around the belts.

I had all belts replaced. Timing and the two belts out out of the timing cove which operates the a/c alternator and power steering. When i turn on the a/c mine squeals on a cold start after hot it goes away. Prolly a cheap belt my mec put on. I noticed on the outter edges its fraying so i tightened it some more the noise went away but its back and i domt want to keep putting more tension on the belt to make it snap! Most generally belt noise is usually caused from either a mis aligned belt or a worn belt.