El Nino and La Nina: How do They Affect Winter in New York?
—Jeni Vogel, Education & Program Coordinator
How do El Niño and La Niña affect the weather? El Niño and La Niña are part of the El Niño-Southern Oscillation cycle or ENSO. This cycle describes fluctuations in temperature between the ocean and the atmosphere in the east-central Pacific Ocean. This pattern can cause weather extremes and typically impacts winters in North America.
La Niña is caused when easterly trade winds strengthen, moving warm water west and pushing cold water to the ocean surface along the South American coast. This causes below average surface temperatures in the east-central Pacific Ocean.
El Niño is the opposite. It is caused when easterly trade winds weaken or reverse in direction. The Pacific Ocean remains warm and can even gain heat. Therefore, the east-central Pacific Ocean experiences above average surface temperatures.
El Niño and La Niña episodes usually last between nine and twelve months, however, they can also last up to 2 years. The frequency of these cycles can be quite varied but tend to occur every two to seven years.
These patterns have both a global and local effect. During a La Niña winter, the Northeast will experience colder weather, the Northwest will experience a wetter than normal winter, and the South will be drier and milder. El Niño winters mean warmer temperatures in the Northeast, drier conditions in the Pacific Northwest, and wetter than average conditions in the Southeast and Southwest.
Source: The Weather Channel
According to The Weather Channel, as the winds from the most recent El Niño cycle change direction, it may be colder in the New England and Northeastern parts of New York this coming winter. Meanwhile, below this line, many will experience warmer than average temperatures. The Weather Channel also suggests that as the easterly trade winds change, the coldest part of winter will occur earlier in the season along the East Coast.
For more information, watch a video explaining El Niño and La Niña.
