rationalskepticism.org

Then there's the matter of where all that water came from and where it disappeared to. Apparently, if all the ice on earth melted (which in itself would create an impossible climatic and physical scenario), there'd be just enough to raise global sea levels by between 70 and 80 metres. Mount Ararat, on which the supposed Noah finished up with his supposed ark, consists of two major volcanic cones: Greater Ararat and Little Ararat. Greater Ararat is the highest peak in Turkey and the Armenian Highland with an elevation of 5,137 m (16,854 ft); Little Ararat's elevation is 3,896 m (12,782 ft). There is no evidence of tectonic plates moving anywhere near the speed necessary to have either of them raised to that height between the supposed flood and now, or for ocean depths to have dropped to their current levels.

As for Snowball Earth, it is not even a theory. It is a hypothesis, and the most recent one is hypothesised to have occurred sometime earlier than 650 million years ago during the Cryogenian period. It would have preceded the biblical flood by about 649.955 million years.