La Niña is back. Will it bring more snow to NJ this winter?


For the second year in a row, a natural climate regime known as La Niña has developed, and forecasters say it could have a big influence on the upcoming winter season in the United States and possibly the remaining weeks of hurricane season in the Atlantic.

The re-emergence of La Niña – which is described as “double dip ”by the National Oceanic and Atmospheric Administration due to its arrival in consecutive years – was triggered by colder than average temperatures in the central Pacific Ocean.

More people may be familiar with the reverse pattern РEl Ni̱o, which occurs when water temperatures in the central Pacific are warmer than average. But El Ni̱o and La Ni̱a conditions play a key role in shaping weather patterns not only in the United States but around the world.

Experts say a strong El Niño tends to cause more wind shear in the Atlantic hurricane basin, limiting the formation and strength of tropical storms and hurricanes. A strong La Niña tends to favor storm patterns with less wind shear, which facilitates the development and strengthening of tropical systems in the Atlantic.

So, will La Niña’s return play a role in the remaining weeks of the 2021 hurricane season? NOAA experts Climate Prediction Center say it’s possible, although the Atlantic hurricane basin – the Atlantic Ocean, the Caribbean Sea and the Gulf of Mexico – remains very calm at the moment with no major storms brewing.

The hurricane season officially ends until November 30, and this season has already been very active, with 20 named storms.

Here’s what a La Nina climate model looks like, with cooler-than-average sea surface temperatures along the equator in the tropical Pacific in September 2021. The trend continued into October, and NOAA says La Nina will likely persist through the winter season. from 2021-2022.NOAA

Impact on winter conditions

In terms of its impact on winter conditions, a La Niña climate model tends to generate colder, snowier winters in the far north of the United States and warmer, drier winters in the southern United States. United.

However, its impact on regions of the northeast and central Atlantic, including New Jersey, is not as constant as in other parts of the country, according to several weather experts, including the climatologist of the ‘State of New Jersey, David Robinson.

“We’re just in a place where we’re stuck between areas where the signals are more consistent,” Robinson said before last year’s La Niña model.

During winters dominated by a La Niña pattern, Robinson noted that “the Ohio Valley and the Great Lakes tend to be wetter than average and the southeast drier. We’re in between, with most of the favorable La Niña rainfall near average, not tilting to an extreme in either direction. “

Forecasters of WeatherWorks, based in Warren County, has analyzed La Niña winters since the late 1980s and found that a strong La Niña pattern typically results in milder winters for the New Jersey area, typically resulting in falls of average or below average snowfall. During some La Niña winters, however, the Garden State was hit by heavy snowfall.

Last winter – when another La Niña model was active – classified as New Jersey’s 29th Warmest Winter on Record, according to Robinson’s weather database at Rutgers University, which dates back to 1895. But winter was also very snowy, with the exception of January.

Statewide, New Jersey was covered with an average of 29.9 inches of snow last winter, almost 10 inches more than normal.

So, will this winter be a repeat, with different La Niña weather and lots of snow in the Garden State?

Jim Sullivan, long-term forecaster at WeatherWorks, thinks a lot depends on whether the jet stream pattern this winter is keeping a lot of cold air trapped in Canada and the northern Rockies. This scenario would limit the amount of snow that falls in the eastern United States, as well as in the central region, Sullivan notes in his early winter outlook for 2021-2022.

Although he sees similarities between last year’s La Niña model – which was considered to have moderate strength – and the looming one this year, which is preferred as minor to moderate, Sullivan said temperatures might not be as hot as they were last winter. .

“My hunch is that it will probably be a slightly colder winter than last year,” Sullivan told NJ Advance Media on Friday. “If it’s colder than last winter, that certainly opens the door” to more snow than average.

However, he added, “if the cold air remains locked in (in the northern Rockies and in Canada) it could limit our possibilities for snow.”

Current weather radar

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Len Melisurgo can be contacted at [email protected].


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