Rutgers climatologist: Expect a 'volatile' winter

PISCATAWAY, N.J. - What kind of winter will it be? Severe as last year's, or milder like two previous ones? Can an early snow in Siberia affect weather in Philadelphia, and what impact will El Niño have?

Rutgers University's Global Snow Lab in Piscataway tries to answer those questions using raw federal data on the snow cover in North America and Eurasia to create maps and long-term climate records to aid forecasting.

Bottom line, the winter of 2014-15 will likely be "volatile" across the region, said New Jersey state climatologist David Robinson, director of the snow lab. "I've been standoffish until now" to make a prediction.

"But I think we'll have a streakier winter - in and out of storms, with it getting cold, then warm," he said. "I don't see us in the depth of cold and snow [like last year] - and staying there."

As frigid air pushed into the area over the last few days, even bringing some snow, data rolled into the Global Snow Lab from the National Oceanic and Atmospheric Administration and the Navy at the U.S. National Ice Center in Suitland, Md.

Robinson works with a graduate student and a technical assistant, crunching and interpreting the numbers to produce online maps. He has also been joined at times by colleagues from other universities, and is expecting a statistical modeler from China this month.

But the actual Global Snow Lab, which has been around since Robinson came to Rutgers 26 years ago, is largely his academic office. There's no sign identifying it.

"The people who use our maps are in the business of seasonal forecasting, telling you what the winter is going to be like," said Robinson, whose year-round research is free to users and has been funded by NASA, NOAA, and the National Science Foundation. "There's the research community, climatologists, private forecasting concerns, and companies" across the world.

Energy businesses need to know when and where to position oil and natural gas supplies for winter. Clothing firms want to know ahead of time where to move merchandise so it will sell. And candy companies want to know whether the weather will affect the price of cocoa.

"It's really important to know where the snow sits so you can make short-term weather forecasts," said Robinson, who enjoys cross-country skiing in his spare time. "It reflects sunlight to space, takes energy to to melt, and suppresses the air temperature.

"If you don't know where the snow is, you'll blow your high-temperature forecast," he said. "And if the snow isn't there, you may grossly underestimate the temperature since the absence of snow leads to warmer temperatures."

Among those using the data is Mark Serreze, director of the National Snow and Ice Data Center at the University of Colorado in Boulder.

The work of the Global Snow Lab represents the "longest satellite data record we have of our global environment," Serreze said. "So it's key for monitoring what is happening to our planet.

"Snow actually drives a lot of what happens in our climate, so we want to know where it is and how much we've got," he said. "Snow data is used all the time by a lot of different agencies, like the National Weather Service."

Many weather watchers and forecasters took note of the Global Snow Lab's report that about 14.1 million square kilometers of snow blanketed Siberia at the end of October, the second-largest area of snow in records going back to 1967.

"There's been found a statistical relationship between the extent of snow cover in October over Siberia and the atmospheric circulation over the North Atlantic in the following winter," said Robinson, 59, who has been the state climatologist for more than two decades. "There is a hypothesis that it will dictate the jet-stream move over the Atlantic, which also influences how cold and stormy we are here along the East Coast.

"If there's abundant October snow, you get a curving jet stream, dipping over the eastern U.S.," he said. "If six or seven times out of 10 you've had extensive snowfall over Siberia and end up with a cold, stormy East Coast, that information provides a valuable long-term forecasting tool. It shows the worth of monitoring that snow cover."

But forecasts can be complicated by other factors. This month, for instance, the former Typhoon Nuri moved into the Bering Sea, displacing the polar jet stream, which dipped south, ushering in the coldest air mass of the season.

That led to freezing temperatures and snow across the Upper Midwest. The arctic air then moved east, eventually causing temperatures to tumble locally and renewing worries about another harsh winter.

"The real challenge is to understand how each one [the Siberian snow and Bering Sea storm] can affect us individually but also collectively as they battle it out for influence and dominance," Robinson said. "You have to look at events and the timing of events."

And then there's El Niño, a warm ocean current that develops after late December along the coast of Ecuador and Peru, sometimes causing catastrophic weather conditions.

"I think it will affect weather patterns, including the subtropical jet stream, which affects the Southeast U.S.," Robinson said. "If it joins forces with the polar jet stream, that's when you can have formidable storms coming up the East Coast.

"It's not always snow but storms," he said. "There are so many factors in play from mid-to-late fall, coming from so many different directions."

The combination of influences suggests "volatile weather patterns over the course of the winter," Robinson said. "Last winter was the most memorable since the mid-'90s in terms of the impact of snow and cold on everyday activities."

The climatologist said he didn't believe we were poised for another such winter.

"It won't be that formidable," Robinson said, "but I don't think this winter will come and go quietly."

Besides, "I've loved snow since I was a kid," he said. "I don't even mind shoveling it."

To find out more about Rutgers University's Global Snow Lab, visit http://climate.rutgers.edu/

snowcover/EndText