Lots of Acorns This Year

I have an oak tree in my yard. It was a couple weeks ago I noticed a lot of acorns on my lawn when I was mowing. Today I was at the Dakota Rice Corn and Soybean Growers Plot Tour at Mike and Kay Peterson's farm. There were a few pick-ups parked under an oak tree. I heard acorns bouncing off the pickups as they fell from the trees. So, why did the oak trees produce many more acorns this year than normal? Does it mean we will have a long cold winter this year?

According to the Old Farmer's Almanac, every few years oak trees produce an abundance of acorns. It is a type of survival instinct. So many acorns are produced that the squirrles cannot eat them all. Maybe then more of them will grow into oak trees? There is no link to a year with lots of acrons and a very cold winter.