A Case For Thunderstorms Causing Sporadic E on 6 Meters.

The mechanism that generates Sporadic E clouds is somewhat mysterious.  In Propagation and Radio Science, Eric Nichols explains one possible mechanism is thunderstorms that are strong enough to break electrons free forming a cloud of free electrons.  A good example presented itself on the evening of May 24, 2019  as documented by two maps of the United States taken simultaneously.  The first is a radar map showing a line of thunderstorms along the Kansas/Missouri border.  The second is a map of PSKREPORTER showing W0QL reports.  W0QL is located in Colorado and the reports are located precisely on the opposite side of the thunderstorms and no where else (except local).  Theorizing, the sporadic E cloud is above the thunderstorms and the signal from W0QL is bouncing off that cloud.

See Propagation and Radio Science, Exploring the Magic of Wireless Communication by Eric P. Nichols, KL7AJ, ARRL Publications, 2015.