Big Strike Over Colorado National Monument
Colorado National Monument
A postive cloud to ground (CG) lightning strike connects with the rim of the Uncompahgre Plateau along the northwest edge of Colorado National Monument. Most lighting in a thunderstorm is negative CG and originates from the bottom of the storm where negative ions accumulate; the lightning connects these with positive ions on the ground. Postive CG originates from the postive ions that accumulate in the upper updraft of the tunderstorm; these strikes connect with negative ions on the ground. Though less frequent, postive CG is usually orders of magnitude more powerful and can reach ten miles from the storm to find a connection. Hence the term "bolt from the blue". Photo © copyright by Chris Eaton.