At around 1730 PST, was walking out of my garage door which faces north looking toward Yucaipa Ridge and Mt San Gorgonio, saw what appeared to be a point of light that glowed through the broken to overcast cloud layer in the direction of Yucaipa Ridge, moving erractically and silently in horizontal and vertical directions at a high rate of speed, appearing, disappearing, reappearing again, and finally disappearing completely within a time frame of approximately 10 seconds. Would have concluded it to be ball lightning, but no thunderstorms in area at the time, and ball lightning seems to move rather slowly, at least the ones that I have viewed that were captured on various videos. I would estimate this object to have been 5 to 10 miles away, operating at altitudes ranging from 5000 ft to 10000 ft above sea level, flying at speeds of over 1000 mph, stopping for a second or less, and then changing directions to pick up speed again.