Oval over Kentfield, CA

The report, as filed

Very loud ongoing noise, similar to a hair dryer or leaf blower frequency, filled the Larkspur/Kentfield, CA, valley area near Marin General. Weather was clear with some light patches of fog. From our terrace, (400 ft. above city street level), in the distance I saw what looked like a huge drone, with a big green flashing light, bright white light with smaller red and yellow lights, but this was not a drone, pretty big aircraft. Slowly making its way up vertically then flew horizontally to about the middle point of Mount Tam, made a right, then started approaching the house. That weird sound became very loud. I looked up at the aircraft, the bottom was black, red lights surrounding the oblong aircraft. The other color lights became stronger as well. It was not a jet/plane sound or shape, didn’t see blades, did not sound like a helicopter or chopper. As it flew over the roof and out of sight, I could still hear the sound of that aircraft for a least 5 t! o 6 minutes later, either heading towards San Rafael, San Anselmo, or Woodacre. Living here for ten years I’ve never witnessed anything like this. I’m very interested about this aircraft. I'm emailing a map with description.

Held as-reported from National UFO Reporting Center (record NUFORC #144092). Witness text is preserved verbatim, including its spelling; nothing is edited beyond formatting.