What No El Niño or La Niña Could Mean for This Winter
Neither El Niño nor La Niña are expected to be present this winter
Neither El Niño nor La Niña is expected this winter but these so-called neutral conditions can still offer clues on what winter could look like in the United States.
The El Niño–Southern Oscillation, ENSO for short, is a climate pattern based on sea-surface temperatures in the central and eastern Pacific and their interaction with the atmosphere. It also determines whether or not El Niño or La Niña conditions are present.
ENSO-neutral conditions will likely be in place this winter (70% chance according to NOAA's Climate Prediction Center), meaning both El Niño and La Niña conditions are expected to be absent.
Often during an ENSO-neutral winter, colder-than-average temperatures are found in parts of the Midwest, Northeast
When ENSO is in a neutral phase, tropical Pacific sea-surface temperatures are usually close to average. Neutral conditions can also occur when ocean temperatures resemble either El Niño or La Niña but the atmosphere does not.
ENSO-neutral conditions do not mean that weather conditions will necessarily be average. In the neutral phase the equatorial Pacific water doesn't push the atmosphere toward El Niño or La Niña.
This makes it more difficult to predict weather patterns over the next several months. It also means other atmospheric forces, such as the Arctic Oscillation, will impact the weather, but these other factors typically are harder to predict weeks in advance.
What to Look For During a ENSO-Neutral Winter
A southward shift in the polar jet stream often emerges during a neutral winter, bringing with it colder-than-average air into portions of the Midwest and Northeast.
Meanwhile, much of the southern tier of the U.S. may end up with a warmer-than-average winter overall. Continue reading
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