Loud screeching noise

[dtmcabbey]

I was driving my 2002 V70-XC last night at about 45 MPH when it started a loud screeching noise that I could not tell where it was comming from. It lasted at least one long long minute. Temp outside was 32F and I was diving up a mild grade. I stopped about 40 minutes later and discovered that my power steering fluid was about 1/8" below the tube so I filled the resivor to the proper level and had no additional issues for my remaing 90 minute drive home.

Has anyone had such an issue? Help!