A new scientific study funded by NASA shows that there will be even more rain and snowfall due to global warming. This latest data indicates that rain could increase as much as 13 percent over the next century. The recent Intergovernmental Panel on Climate Change predicted a maximum rainfall increase of 8 percent. So this new satellite-based data may lead to rejiggering currently used climate change models.
The whole report is now available online. You have to pay, or be a member of the American Association for the Advancement of Science (AAAS) to access the complete PDF.
Don't expect this new data to mean Phoenix will become a rainforest. Previous predictions still hold: wet places will get wetter, and more intense storms. Dry areas like the southwestern United States will likely get even dryer. Even though global warming is expected to put more moisture into the atmosphere, it won't be evenly distributed.