A Groundhog Day Analysis

03/06/2014

Out of respect for the colder/snowier than average winter we've had around the country this year, and my sentimental attachment to the movie Groundhog Day, I did a little digging into our lovable Punxsutawney Phil and his record of "predicting" weather.

Some fun facts:

1. There are several other furry prognosticators around the country, notably Sir Walter Wally (Raleigh, NC).

2. February 2nd, which is about halfway between the winter solstice and spring equinox, has been long believed an important transition into the new harvest season. The Celts called this time Imbolc, a sign to plant new crops. Some Christians refer to Feb. 2nd as Candlemas, the feast of the Purification of the Blessed Virgin. The Middle Ages saw a rise in the belief that animals like the badger and bear would wake from hibernation, and that the sight of a shadow indicated six more weeks of winter.

3. The original animal representing this historic day was a badger; clearly, we celebrate the groundhog. Both animals are furry and fat, so it's fine.

Here's where the stats come into play...

Since 1895, Punxsu-Phil has seen his shadow 100 times (winter prediction), has not seen his shadow 15 times (spring prediction) and has failed to predict 5 times (unacceptable).

If you consider "winter" to be the average temperature in Dec and Jan, and the transition to "spring" the average temperature in Feb and Mar, and then make an assumption that the temperature must transition at least 35% higher to be "spring" or remain within 35% higher to continue "winter", then Phil has an 80% chance of predicting Feb/Mar weather.

The winter has driven me so crazy that I spend the time analyzing mammalian weather predictions in hopes of getting that much closer to sunny weather and a tan face.