The 2012 weather numbers are in, and it's official: Long Island experienced its warmest year since records started being kept more than six decades ago.
The mean temperature for the year in Upton was 54.22 degrees -- the highest mean temperature in the 63 years of weather data collection at Brookhaven National Laboratory, a spokesman for the lab said Thursday.
Central Park, where data go back to 1869, also recorded the warmest year on record, with an average temperature of 57.3, the weather service said.
Indeed, the year was the warmest "on record for 23 of the 35 major climate sites in the Northeast," said Samantha Borisoff, a climatologist in Cornell University's Department of Earth and Atmospheric Science and at the National Atmospheric and Oceanic Association-supported Northeast Regional Climate Center.
It's all thanks to an early-in-the-year jet stream pattern that allowed the area to "dodge brutally cold air," setting "the stage for above-normal temperatures the rest of the year," said Brian A. Colle, professor in the School of Marine and Atmospheric Sciences, Stony Brook University.
In fact, March broke the record in Islip for the highest average temperature for that month -- 55.7 degrees, up from the previous record of 53.5 degrees in 2010, the weather service said.
While the Northeast got a break, the jet stream dipped down into central and Eastern Europe, bringing a cold spell and heavy snow, Colle said. People there and in parts of Alaska would have thought the winter "brutal," he said.
"Last winter was a 180-degree flip from the previous two winters," in which the jet stream dipped down over the United States, bringing cold air, said Bob Smerbeck, senior meteorologist with State College, Pa.-based Accu-Weather.
While 2012's pattern comes along naturally every five years or so, climate change can make above-normal temperatures "even more above normal," by an "extra half a degree or so," and result in such record highs, Colle said.
As for snowfall, Islip measured 9.2 inches for the year, down from the norm of 24.8 and 2011's 40.7 inches. Indeed, Colle said, such low-snowfall years are interspersed between some years with "remarkably high snow amount."
As for the year's defining weather event, Smerbeck said it's hard to link 2012's warmer temperatures to superstorm Sandy.
Still, he said, some researchers are suggesting that diminishing sea ice could lead to conditions conducive to the development of the major blocking pattern that prevented Sandy from turning out to sea.