Instead of dissipating, the storm continued to grow as it moved towards Black Mesa to the east. The classic mushrooming thunderhead was lit externally by the gibbous moon and internally by its own flashes of lightning. Long exposures could capture both the dim, but steady, light from the moon on the clouds as well as the short, but intense, radiance of the lightning. The long exposure also revealed a surprising amount of blue in the sky. The stars were definitely out and shining by this time and the eye would not normally perceive this much color.