Sounds like what i just went through last week,my ac leaked its 5 ounces of oil out a few month ago and the bearing started rumbling so i just ran without ac on,then even without it turned on it started howling and i knew it was a matter of time b-4 it seized up and stranded me so i figured out the length of belt i would need to eliminate the compressor until spring and when i have extra cash/time.
http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_Poly-Rib&174;-Belt-Dayco_19270624-P_1063_R|