This is an awesome picture. Supercell Thunderstorm by Sean Heavey, nationalgeographic: A supercell thunderstorm rolls across the Montana prairie at sunset. This was a winning shot in the 2010 National Geographic Nature Gallery Photo Contest.
PRO Ryan McGinnis Burwell Monster A vertical shot of the monster HP supercell that pummeled the open range north of Burwell, Nebraska, June This storm had several rain-wrapped tornadoes earlier in the storm's lifecycle.
A Supercell Thunderstorm Cloud Over Montana Image Credit & Copyright: Sean R. Heavey Explanation: Is that a spaceship or a cloud? Although it may seem like an alien mothership, its actually a impressive thunderstorm cloud called a supercell