Bright White colored, Saucer shaped UFO, camouflaged to blend with the clouds.Approximately 1 km South of the former US Clark AirForce Base, I was standing and facing east, smoking a cigarette and admiring the huge, extremely white, thick fluffy clouds hanging still, in the beautiful dark ocean-blue sky. There was no noticeable wind, the temperature was warm in the mid 70's.I witnessed the under side of a saucer shaped UFO, color white as the cloud, slowly emerged out of the cloud into the blue sky in a Northernly direction and hovered motionless for 10 seconds but maintained a close proximity to the cloud and then returned into the cloud, no longer visible. After 1 minute the UFO emerged out of the cloud for another 10 seconds and once again returned into the cloud.I was alone, had no camera. I believed it to be a UFO saucer shaped aircraft.One week prior to this, I witnessed in the early morning 6:00am, chem trails being laid down by a winged aircraft in the same area before it travelled far enough to lose sight of it.((NUFORC Note: Witness indicates that the date of the incident is approximate. PD))