Effect of X-class Solar Flare on 40 Meter Propagation

WSPR data for North America is summarized to examine the impact of a reported x-class solar flare.  The data is divided into distance categories to examine impact on different propagation methods, assuming that distance indicates propagation method. Very short distance (under 100 mile) for non-ionospheric, short distance (100 to 500 miles) for NVIS, medium distance (500-1500 miles) for E-layer propagation and longer distance (over 1500 miles) for F-layer.  Signal to noise ratio is plotted by hour for the date of the flare. The impact of the flare is shown as a sudden decline in SNR for all distance ranges.  While communications under 100 miles were initially presumed to involved non-ionospheric propagation, the flare impact at this distance indicates otherwise. WSPR data is also evaluated for its suitability in propagation analysis, noting strengths and weaknesses.