During a balloon flight into and above the stratiform region of a mesoscale convective system, we observed three xray pulses while the balloon was at an altitude of approximately 15 km MSL (atmospheric pressure of 130 mb). These pulses were one to two orders of magnitude above the background xray count rate with peak fluxes between 37 and 270 (cm(2)-s-sr)(-1) and durations of about one second. No significant electric field was measured at the time of these pulses.