The United States could experience the effects of two major weather patterns at the same time as a powerful El Niño continues to strengthen in the Pacific Ocean and the Arctic polar vortex shows signs of an unusually early collapse. The two developments could influence temperatures across the country in the coming weeks, bringing brief periods of colder weather to some regions.
According to a Newsweek report, meteorologists are watching both developments closely. While El Niño is expected to be the main influence on US weather this winter, a weakened polar vortex could allow Arctic air to move south and bring temporary cold spells.
Super El Niño expected to strengthen this winter
El Niño is the warm phase of the El Niño-Southern Oscillation (ENSO) climate pattern. It develops when ocean temperatures rise above average across the central and eastern equatorial Pacific, along with changes in trade winds.
The current El Niño has been strengthening for months, and National Oceanic and Atmospheric Administration (NOAA) forecasters expect it to reach peak strength this winter.
A strong El Niño can influence weather across different parts of the United States. It generally brings warmer and drier conditions to northern regions, while the southern states can experience wetter and stormier weather. Higher snowfall is also possible in parts of the Intermountain West and the higher elevations of the Southwest.
{{/usCountry}}A strong El Niño can influence weather across different parts of the United States. It generally brings warmer and drier conditions to northern regions, while the southern states can experience wetter and stormier weather. Higher snowfall is also possible in parts of the Intermountain West and the higher elevations of the Southwest.
{{/usCountry}}Also Read: El Niño risks may push global food prices higher in 2027; full impact to emerge gradually: Report
Early polar vortex disruption raises cold weather concerns
The polar vortex is a large area of cold air and low pressure surrounding the Arctic. It exists throughout the year but becomes stronger during winter. When it weakens or becomes disrupted, cold Arctic air can move south towards the United States.
Meteorologists have raised concerns about the current weakening, which is happening earlier than usual. WFLA-TV chief meteorologist Jeff Berardelli said the disruption appears to be the earliest on record, occurring roughly a month earlier than previously observed.
A major disruption can happen during a sudden stratospheric warming (SSW) event, when temperatures in the stratosphere rise rapidly and disturb the strong winds surrounding the Arctic.
Meteorologist Max Velocity said a split in the polar vortex could push some of the cold air towards lower latitudes, potentially affecting the US during the second half of November. However, this does not guarantee a major cold outbreak.
Midwest and Northeast could see temporary cold spells
The northern Midwest and Northeast are expected to experience below-average temperatures during the first week of November. This would follow a period of warmer and drier weather across both regions.
However, the colder conditions may not last long. AccuWeather long-range meteorologist Alex DaSilva told Newsweek that the early timing of the polar vortex disruption means there may not be enough cold air available to produce a major Arctic outbreak.
DaSilva also said El Niño is likely to have a stronger influence on US weather during November, with above-average temperatures expected across much of the country for the rest of the month.
Also Read: El Nino could be unprecedented, may rise to 3.8°C above average between Nov-Jan: WMO
El Niño expected to remain the main winter influence
Although the polar vortex disruption could increase the chances of colder weather in the coming weeks, meteorologists have warned against assuming that a major freeze is certain.
Berardelli said a weakened polar vortex could allow Arctic air to move into the United States, Europe and Asia in the following weeks. However, he added that the outcome was not guaranteed because El Niño was having a strong influence on the overall weather pattern.
DaSilva also stressed that the early disruption does not determine whether another polar vortex event will happen later in winter, when colder conditions could make its effects more significant.
AccuWeather meteorologists are still forecasting a very warm winter across the Northeast and northern Midwest. For now, El Niño is expected to remain the main driver of US winter weather, while forecasters continue to monitor the polar vortex for further changes.