New York's winter of 2019 might be a little less frigid but with a bit more precipitation than usual, though government scientists, who issued their December-through-February forecast Thursday, cautioned weather patterns could surprise, confounding predictions.
And this winter's weather might shift back and forth between the extremes.
“Without either El Niño or La Niña conditions, short-term climate patterns like the Arctic Oscillation will drive winter weather and could result in large swings in temperature and precipitation,” Mike Halpert, deputy director of the National Oceanic and Atmospheric Administration's Climate Prediction Center, said in a statement.
El Niño is the term used when the Pacific Ocean by the equator is warmer than usual; La Niña is the opposite, with colder-than-usual ocean temperatures in the area, NOAA says. Both phenomena can greatly influence weather in the United States and Canada.
NOAA defines the Arctic Oscillation as an "atmospheric circulation pattern over the mid-to-high latitudes of the Northern Hemisphere," which can steer storms and the jet stream.
For long-range, seasonal forecasts, the College Park, Maryland-based experts assess three probabilities for temperature and precipitation: below-average, average and above-average.
"In the mid-Atlantic, for temperature, we have a slight tilt in the odds towards a warmer-than-average winter," Halpert told reporters on a conference call.
Mid-Atlantic states, including New York, face a 38% chance of a warmer winter, a 33% chance of average winter temperatures, and a 29% chance of below-average, Halpert said.
In New York, there is a "slight tilt towards wet, but very slight," he said.
None of the nation is expected to have below-average temperatures.
Warmer-than-normal temperatures are expected for much of the lower 48 states, from the West, across the South, and along the Eastern Seabord, NOAA said. "The greatest likelihood for warmer-than-normal conditions are in Alaska and Hawaii," the agency said in a statement.
No predictions could be made for the Northern Plains, the Upper Mississippi Valley and the western Great Lakes, as there are equal chances that any of the three probabilities will occur.
More precipitation than average is predicted for Alaska, Hawaii, parts of the Northern Plains, the Upper Mississippi Valley, the Great Lakes, and parts of the Mid-Atlantic and Northeast, the forecasters said.
A drier-than-normal winter seems most likely for Louisiana, parts of Texas, Mississippi, Arkansas and Oklahoma — and areas of northern and central California, according to NOAA. The rest of the country falls into the "equal chances" category.
Trying to figure out which past winter the 2019 season might resemble is impossible, as there is simply too little data. "The reality is to try and accommodate all of the various modes of climate variability, you need thousands of years of data to even begin to look at that," Halpert said. "We have far short of that."
Here are the mean measurements for temperature, precipitation and snowfall for Long Island for each of the three winter months. Precipitation includes both rain and melted snow; snowfall can be greater because its volume is greater when frozen. The numbers are based on statistics that date back to 1963.
Precipitation: 4.06 inches
Snowfall: 5.4 inches
Precipitation: 3.64 inches
Snowfall: 6.7 inches
Precipitation: 3.26 inches
Snowfall: 7.1 inches
Source: National Weather Service