Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.
By: Dr. Jeff Masters , 3:27 PM GMT on February 02, 2010
Punxsutawney Pennsylvania's famous prognosticating rodent, Punxsutawney Phil, saw his shadow this morning. According to tradition, this means that a solid six more weeks of winter can be expected across the U.S. From the official web site of the Punxsutawney Groundhog Club, groundhog.org:
Here Ye! Here Ye! Here Ye!
On Gobbler's Knob on this fabulous Groundhog Day, February 2nd, 2010
Punxsutawney Phil, the Seer of Seers, Prognosticator of all Prognosticators,
Awoke to the call of President Bill Cooper
And greeted his handlers, Ben Hughes and John Griffiths
After casting a joyful eye toward thousands of his faithful followers,
And a bright sky above me
Showed my shadow beside me.
Six more weeks of winter it will be.
How did this this crazy tradition start?
It all started in Europe, centuries ago, when February 2 was a holiday called Candlemas. On Candlemas, people prayed for mild weather for the remainder of winter. The superstition arose that if a hibernating badger woke up and saw its shadow on Candlemas, there would be six more weeks of severe winter weather. When Europeans settled the New World, they didn't find any badgers. So, they decided to use native groundhogs (aka the woodchuck, land beaver, or whistlepig) as their prognosticating rodent.
What the models say
The latest long-range runs of the ECMWF and GFS models show the jet stream following a typical El Niño winter configuration. A northern branch dipping down over the Northeast U.S. will bring seasonably cold temperatures to the eastern half of the country, with a compensating ridge of high pressure bringing milder temperatures to the Northwest U.S. (and the Winter Olympics in Vancouver, Canada). A second branch of the jet stream will be active across Southern California, Texas, and the Southeast U.S., bringing cooler and rainier weather than average. There are no indications that the jet stream will get "stuck" in a high-amplitude pattern that will bring long-lived record cold to any portion of the country, such as occurred over Florida in early January. At this point, I don't see any reason to disagree with Punxsutawney Phil's fearless forecast of a normal six more weeks of winter.
Figure 1. Departure of winter temperature from average for February. This is a very typical pattern for an El Niño winter. Image credit: NOAA Climate Prediction Center.
My next post will be Wednesday, when I plan to talk about the status of this year's El Niño.
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