Mid-morning peak in light rainfall appears as clouds and fog at Purchase Knob in the Great Smoky Mountains National Park. Light rainfall is the most reliable and most frequent form of rainfall in the ... more 
Mid-morning peak in light rainfall appears as clouds and fog at Purchase Knob in the Great Smoky Mountains National Park. Light rainfall is the most reliable and most frequent form of rainfall in the region, contributing 50 to 60 percent of the less 
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LiveScience.com | Photo By NASA/Barros
Mon, Dec 30, 2013 3:05 PM EST