Forecasters said La Niña conditions have developed over the past month and are expected to continue into the winter.
Jonathan Marcus with the National Weather Service in Jackson said it is difficult to predict specific temperatures and precipitation types in advance, but the La Niña weather system allows meteorologists to predict some upcoming conditions based on how conditions have looked in Kentucky in the past.
“It looks like we are favored for a wetter than usual winter. And that is typical for those La Niña patterns here in the greater Ohio River valley. However, when it comes to the temperature outlook, we are seeing equal chances of above and below normal temperatures, which means there’s probably going to be some variability as we go throughout the season,” said Marcus.
A La Niña weather system occurs when sea-surface temperatures are cooler than average and the atmosphere is affected for at least three months. A feedback loop created by rising and falling wind and sea-surface temperatures reinforces La Niña conditions.
La Niña systems usually last nine to 12 months, but the last occurrence stretched from 2020 to 2023.
Marcus said in the Ohio River valley, the La Niña weather system causes a wetter winter. He said meteorologists are currently unable to predict whether a wetter winter will mean more icy conditions.
“We can start getting a sense of that about seven days out, but really we’ll know a few days out ahead of when an ice event is going to occur, just because there are four different types of precipitation that occur during the winter and it’s really difficult to predict the small-scale temperature details throughout the atmospheric column that determine those precipitation types this far in advance,” said Marcus.
Though conditions will be wetter, officials said the Ohio River valley usually experiences a lower amount of snowfall under La Niña conditions.