A few weeks ago, I was out of the house at 8:15a.m. for an appointment at a salon about 15 mi. away. Blue skies and not a cloud. Same thing when I returned home around 11:00a.m. I only stopped home for about 5-10 minutes and then went back out. When I got to the end of my block where there are a couple farms, I saw 3-4 planes and then at a very high altitude there was one plane in the lead, two following and then two more following. Went into a store and one hour later, the skies were now like a white sheet.