Today famed groundhog Punxsutawney Phil poked his head out of his burrow and saw his shadow, meaning (according to the old German superstition) that we can expect six more weeks of winter. But the crowd gathered in Pennsylvania to see the rodent’s prediction stood in pre-dawn temps hovering just above freezing, almost twice the average for Groundhog Day there.
But many people around the country are wondering if Phil is a little off since they’ve hardly seen any winter and can’t really imagine six more weeks. Across the Midwest where temps hovered in the 60s people are thinking spring. Plants are poking through the dirt and trees are beginning to bud.
According to the National Weather Service Midland, Texas has seen more snow this year than Chicago or Minneapolis. Outside of Alaska the U.S. has been spared much of the harsh cold and snows of winter. On the last day of January Washington D.C. almost reached 70 degrees and the cherry trees were beginning to bud.
That’s quite a contrast to last Groundhog Day when a big blizzard crippled much of the country, killing 36 people, cutting power to millions and causing $1.8 billion in damage. For the season, it appears that just about every place is low on snow. Except Valdez, Alaska where 328 inches have fallen — 10 feet above normal, stranding residents and forcing emergency oil deliveries to keep the heat on.
Some are left wondering if this weird winter weather is a sign of global warming? The short answer is probably not. No one weather occurrence can be linked to climate change but trends over time paint picture that shows the planet is warming. There is a clear long term trend that is melting ice at each pole and on glaciers around the world.
Tom Wagner, the cryosphere progam manager at NASA says this winter weather pattern is likely within the zone of natural variability. While snow seems to be a no-show this year for most parts of the country, Wagner says that we actually had less snow at this time in 2006.
NASA attributes our mild winter to two atmospheric factors. The first is a strong positive Arctic Oscillation. That means that all the cold air that generally pushes south in winter is staying closer to the North Pole. On top of that we also have a La Nina year occurring in the Pacific Ocean where waters are cooler than average. That sends dry air over North America.
Wagner says, “The upshot of all this is that we wind up with all the snowstorms going to places like Alaska whereas here in the lower 48 we will wind up without a lot of snow.”
When you put those two pieces together most of us get the winter that wasn’t.
Here’s how it works.When there is a strong positive Arctic Oscillation the winds spin fast in the Arctic and trap the Jet Stream air current far to the north. In the past few days the oscillation switched from positive to negative but National Climate Prediction Center deputy director Mike Halpert says the switch didn’t happen the way it normally does.
The cold jet stream dipped in Europe and Asia but remains bottled up over North America. That’s because another meteorological phenomenon called the North Atlantic Oscillation is a little out of whack. Normally the AO and NAO are in lockstep but right now the National Weather Service satellites show the NAO is staying positive while the AO has gone negative. In a nutshell, that inverse in phase is a bit unusual and is preventing the cold air from descending over much of North America.
Halpert says 90 percent of the time the North Atlantic and Arctic oscillations are in synch.
If the groundhog is right and winter isn’t over yet then Jake Weltzin’s concern may have some merit. The U.S. Geological Survey ecologist is worried that trees and plants that are budding early may not bloom when the “inevitable deep freeze returns.”
Weltzin tells the Associated Press, “If you think about plants and animals being kind of biologic thermometers, they are indicating a very early spring.” He adds, “And, that’s a problem.”
Even though the U.S. has one-fifth of its usual winter snow cover and temperatures are unseasonably warm in many areas, the northern hemisphere is experiencing average winter snowfall as a whole. The Global Snow Lab at Rutgers University found January to be the third-least snow month on record in the contiguous U.S. since record keeping began in 1967. But Europe and parts of Asia are stuck in the deep freeze. Europe and Asia experienced the ninth snowiest January since 1966.
Snow fell in islands on the Adriatic Sea. Parts of the Black Sea froze near the coastline of Romania. And 112 people died from a vicious cold snap that left England coated in ice and the Ukraine shivering from frostbite.
Back in the U.S. New Jersey state climatologist David Robinson says he’s disgusted that duffers are golfing on his winter cross-country ski course. For the northeast U.S. the last few months have been among the warmest and least snowy on record. The Northeast Regional Climate Center at Cornell University shows the region’s temperatures are five degrees warmer than average.
They are also golfing in Dayton, Ohio where Tuesday’s high was a balmy 60 degrees.
Ecologist Weltzin thinks if there is a big freeze after the plants begin to bud that will affect wine grapes and other fruit this year.
Jeff Masters, the director of meteorology at Weather Underground tells the Associated Press, “We’ve just had a remarkable run of unusual winters in the past six years globally.” He’s in the middle of the winter snowbelt in Ann Arbor, Michigan where he says winter hasn’t yet arrived.
Along Lake Erie which is usually frozen in the winter, a ferry service that shuttles passengers to islands began winter routes for the first time in six years.
Wagner says it’s hard to predict what the next two months will bring. When there is a positive Arctic Oscillation you get real variation in the position of the jet stream. So he says the weather in February and March “is anyone’s guess at this point.”
Punxsutaney Phil doesn’t rely on sophisticated computer models or satellite imagery to understand the complex nature of the atmosphere, weather and climate. He just looks up and if he sees his shadow he returns to the comfort of his hollow for another six weeks. Since he began forecasting the seasons in 1886 he has seen his shadow 100 times.
But he’s never wrong about winter’s end because according to Mike Johnston, the vice president of the inner circle (the top-hat toting group of men that run the Groundhog Day event) says Phil is “incapable of error” because he doesn’t factor geography into his predictions. Johnson says since the groundhog predicts six more weeks of winter this year, “I guarantee you someone’s going to have six more weeks of winter.”