No. 2: Extreme Forecast

When a brutal Nor’easter swooped in on October 29, battering the East Coast with wind and snow and killing more than 30 people, it seemed a foreboding omen. Will this winter break records in snow? Will the East Coast have another Snowpocalypse?

As it turns out, the forecast says the mid-Atlantic has a chance of normal winter weather — or not. A wild-card atmospheric pattern in the Arctic could bring above-average amounts of snow to the East Coast, but the real Snowmageddon-style blizzard is much more likely to happen in the northern Midwest, including Chicago. Thanks to the second winter of La Nina, which is a cooling of water temperatures in the tropical Pacific Ocean, forecasters are also predicting a warm and dry winter in the South, while the West Coast will be smacked repeatedly with rain.

The persistence of La Nina
La Nina might just stick around for spring and the summer, too. The National Oceanic and Atmospheric Administration, which encompasses the National Weather Service, and the Old Farmer’s Almanac both predict a wet, rainy North and a dry, hot South in 2012.

“It’s unfortunate for some southern states,” says Matthew Larsen, associate director for climate and land-use change at the U.S. Geological Survey. “Texas has been in a severe drought for some time. If we’re looking at continually below-normal precip there, then that’s not going to be good for them.”

More extremes in the forecast
Up north, on the other hand, large swaths of North Dakota spent the summer months underwater, as floods forced 12,000 people to leave their homes. Unfortunately, this summer might not bring relief.

But what about storm seasons? That’s all up in the air, so to speak. Thanks to global climate change, the temperature of the atmosphere has increased over time, and, as Larsen explains, that means the atmosphere holds more moisture. In turn, storms are getting bigger and more violent, so in the coming year, we shouldn’t be shocked if we have at least one monster blizzard, tremendous hurricane, or epic flood that overwhelms existing dams and levees.

What climate change has to do with it
Those who’ve lost a loved one or a home in a natural disaster know how devastating these events can be. And many more people would feel the effects if a natural disaster were to threaten our water supply or cause entire crops to be wiped out.

With the atmosphere changing, the U.N. World Climate Research Program has attributed some of the deadliest global catastrophes, like the floods in Pakistan and the fires in Russia in 2010, to what they called “blocking episodes,” in which rain doesn’t move into or out of a particular region. According to a Pew Research Center report, an increasing number of Americans believe there is “solid evidence” that this global warming is occurring.

“You can’t say with absolute certainty that any one of these events is strictly related to climate change,” Larsen says. “But we can say these type of events are what we’re likely to see in the changing climate scenario in the future. The potential is for more water to be delivered because of the warmer atmosphere, and the inverse, of course, is that we’re also seeing models predicting what are called deeper droughts, which are more intense and longer lasting.

“The entire atmosphere is changing, based on the physics of the system we’re perturbing. We’re basically doing this big experiment on our planet, and we don’t really know the outcome.”

Lisa Hix is a freelance writer and former Yahoo! editor who has been published in the San Francisco Chronicle, Glamour, and Bust. She’s currently an associate editor at Collectors Weekly and a KQED Arts blogger. Find her on Twitter.