This has occurred frequently over the last several years and has been seen multiple days during the week. i have been looking up at the stars for over 50 years. i was in the u.S. navy for 6 years as a radar operator/technician on a track guidance air defense system. i currently work for a government agency maintaining electronic and computer systems, one is a weather radar. i know what aircraft look like, i know what a tumbling spent booster looks like, i know what an iridium flare is, i know older satellites had multiple solar fins that rotated and flashed, i know what a meteor is, so what i am seeing does not fit the norm. i have seen this flash usually between 7 pm and 10 pm according to the season. it usually happens ene of my back porch at about 45 to 70 degrees of elevation. i have seen this flash in other directions, but primarily east as that is the direction my back porch faces. the flash last between 1 and two seconds and is intensely bright. it reminds me of and old kodak flash cube. usually there is just the one flash and that is it. there is no watching a faint body move across the sky as the sun no longer strikes the object directly. on a few occasions i have seen a dim flash and several seconds later i will see the intense flash. the only description i can use for an analogy is a sci-fi show that shows someone standing on a planet and the star ship warps and you have the flash. if what i am seeing is a natural phenomena please let me know.