Groundhog Accuracy

I recently became curious about the accuracy of this tradition.  If a groundhog’s shadow can actually predict the weather, I wanted to know why.  I came to find out that the accuracy is horrible - at least for Punxsutawny Phil, who is probably the most famous of the many groundhogs that are watched on Groundhog Day.  I read he was at 39%.  Um, okay, so he’s actually worse than random chance.  In fact, based on those statistics, I would say maybe we should revise the whole thing and say that if he sees his shadow, we’re in for an early spring.  Right?