Object in daytime sky reflected light twice then disappeared.Driving southwest at around 17:30 with another passenger and we saw a sphere in the sky that seemed to blink in and out of existence. Very similar in appearance to the planet Venus as it appears in the evening sky, yet this was before sundown. Sky was bright and well lit, and object was gray and reflective. It appeared briefly, as if it had been there all along and was suddenly reflecting sunlight. It disappeared then "reflected" light once more before we lost line of sight due to surrounding treeline.