Per an article found here : NOAA fall Foliage , it states that the color change process is interrupted and some leave may not make its full change before the leaves fall from the trees to get ready for winter.
I took some pictures yesterday while I was in a commercial park. It is nice that business put effort to decorate the landscape to make it a nice place to be. The last pic here is from Blue Bell, PA, it is a good indicator of what a tree looks like halfway through its color change. In the background you can see a few trees in different stages. One tree had it's leaves fall off much earlier, could have been from storms we had before.
|a fall of all colors|
|Red Reflections of fall|