Watched a bright blue ball, in the evening, for about three blocks in a residential area in Northeast Portland. It was about 50 feet overhead.

Went for an evening walk in a residential neighborhood in NE Portland.  While walking I noticed a blue cast on a lawn.  I looked over at the house thinking that it must be Christmas lights not yet taken down, but there were none.  Thought nothing more about it.  About five minutes later I again noticed the blue cast on a lawn.  This time I looked up.  Directly overhead was a bright blue ball.  Apparently it had been following me.  I stopped and the ball contined moving.  I estimated it at about 100 foot above the ground, and about 2-3 feet in diameter.  I based this estimate on a tree that it passed over.  It moved very slowly for about a block, then banked left but continued moving.  When it banked left a bright orange light came on in the center of the ball.  I watched it move for about 2 more blocks, then it simply disappeared.  I looked for searchlights or any lights in the sky but there were none.  I then became quite frightened and returned home. I retraced my steps the next day.  No Christmas tree lights.  I revised my estimate of height to about 50 feet above the ground because the tree that I used for estimating was much shorter than it appeared in the dark.  I mentioned the blue ball to my brother who suggested that it might be ball lightning.  I checked the weather and there was some lightning in the Portland area that evening.  Have never seen anything like it before or since.  The blue ball was simply beautiful Background.  I'm ((age deleted)) and recently retired but at the time was working as a manager for the State ((deleted)) agency.