El Niño and climate change shake up CT's winter outlook
A new seasonal outlook shows southern New England could have an unseasonable winter, with federal forecasters predicting that temperatures and precipitation levels are “leaning above'' normal for the region.
This month’s temperatures have already been trending higher than normal, according to Connecticut Public Meteorologist Garett Argianas. There’s even potential for record high October temperatures this weekend.
Human-driven climate change plays a role in this, along with El Niño, which can affect temperature and precipitation and increase the chances of extreme weather events. This comes in the wake of record-breaking rainfall in parts of Connecticut and New England this year.
“Unfortunately, it looks like that's going to continue to be the case moving ahead as we have more of these heavy precipitation events,” Argianas said.
Even if the winter is trending warmer and wetter on average, there could still be variability throughout the season, Argianas said. That may include bouts of cold temperatures and drought, along with snow.
Despite projected warmer-than-average temperatures this winter, specific atmospheric conditions could create powerful nor’easter storms in the region, said Jon Gottschalck, chief of the operational prediction branch at NOAA’s Climate Prediction Center.
“Certainly [there] will be times when the cold air and moisture will be timed right, such that you can get some pretty large snowstorms,” Gottschalck said. “There's a lot of moisture available to them because of El Niño, which produces considerable moisture available for some of those storms.”
The shift to El Niño is generally tied to disruptions in the atmospheric patterns and the jet stream stemming from the Pacific Ocean, which is already warmer than usual, as NASA continues to report average sea surface temperatures hitting record highs.
“That's just adding to the generally warmer temperatures we have across much of the oceans, and also the positive temperature trends that we see over land,” Gottschalck said.
Historical trends, based on data from the National Centers for Environment Information, since the 1950s show El Niño years often break temperature records, and global surface temperatures have been steadily increasing.
However, experts like Argianas said that forecasts like NOAA’s winter outlook are always subject to change.
“There's not much predictability moving that far ahead in time,” Argianas said. “So we'll have to see how things shake out as we get into the next year.”
Federal weather officials recommend people pay attention to NOAA’s shorter-term outlooks that can prepare people for any necessary decision making.