The northern and western United States can expect warmer-than-normal conditions this year, according to the National Oceanic and Atmospheric Administration’s 2018 winter outlook report.
The effect of El Nino is expected to be fairly weak, but it may still cause warm and dry conditions in the northern United States, Mike Halpert, deputy director of NOAA’s Climate Prediction Center, said in the report.
El Nino is a fluctuation in temperature between the ocean and the atmosphere, linked to warming in ocean surface temperatures in the Equatorial Pacific, according to the National Ocean Service.
In winter months, El Nino tends to cause wetter weather and increased precipitation in the South and drier conditions in the North, according to NOAA’s winter outlook report.
While Connecticut winters have been changing over the past few years, there is not yet enough data to support the development of any kind of pattern, said Xiusheng Yang, a University of Connecticut professor in the Department of Natural Resources and the Environment, as well as the Director of the Connecticut State Climate Center.
“In the past years, we have abnormal winters… we have a warm winter, we have a cold spring. And that was considered abnormal,” Yang said.
Along with changing temperatures, Yang mentioned a time shift in changing seasons as well.
“We (used to) think winter was December, January, February...in the past few years, it became January, February, March,” Yang said.
Connecticut winters have started to see cooler temperatures and increased snowfall occurring later in the season – this is why winter feels warmer and spring feels cooler, Yang said.
Along with unusual seasonal temperatures, Yang said that Connecticut is also getting an abnormal amount of rainfall.
“So far, the rain is more than normal...just in the past month, two months,” Yang said.
In regards to New England precipitation, Yang explained that the unusual rainfall is part of a bigger picture. Large-scale cyclones are caused by cold air from Canada and warm air from the south, which develops into a big stormy “syndrome” in the Central United States before migrating to the east coast, Yang said.
“That kind of weather normally starts in December, so this year it’s kind of earlier (in November),” Yang said.
Yang said it’s important to understand that more extreme temperatures rarely affect the mean temperature. Instead, these extreme data points affect the variation in temperature.
The biggest takeaway from the unusual weather is that there has not been enough of it to identify a shift, Yang said.
“If there’s a change in precipitation pattern, it’s kind of new; we don’t have the historical data to generate (that) kind of pattern,” Yang said.
Natalie Baliker is a campus correspondent for the Daily Campus. She can be reached via email at Natalie.Baliker@uconn.edu.