Two black cloud flying into the wind.

I am a 77 year old male..
I was walking with my 40 year old son and 35year old granddaughter at 18:50 hours when I saw what looked like two small black clouds that were shaped like a widened W.
The sky was clear accept for a few white clouds.
wind was blowing from the west.
I said to the kids look those two clouds look like space ships.
Then the lower cloud turned around and headed southwest into the wind.
About thirty seconds later it looked like it vaporized and disappeared.
About a minute later the second cloud did the same thing. ((13 digit number deleted))