Snowier, Colder Winter Expected For PA This Year

PENNSYLVANIA — The development of La Niña for the second year in a row could bring an even snowier and colder winter to Pennsylvania, as well as exacerbate the finals months of the Atlantic hurricane season, according to weather forecasters.

A weather forecaster based in New Jersey predicts that the upcoming winter will generate several snowstorms based on long-range projections. According to the NY NJ PA Weather forecasting company, the impact of the winter storms and how much snow falls in the region will depend on the interaction between the La Niña weather pattern, how strong or weak the polar vortex becomes, and how much atmospheric blocking is in place.

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"This winter, much like last year, there will be several storms that will feature transition events of snow, to sleet and freezing rain, and finally rain," meteorologists said.

The La Niña phenomenon, which occurs when water near the equator in the Pacific Ocean is cooler than average, has more evidence impacts on the climate in North America in the winter, according to the National Oceanic and Atmospheric Administration.

“This La Niña is expected to be of similar intensity to last winter (weak to borderline moderate), which means it may not 'overwhelm' the pattern but will be a factor,” said Jim Sullivan, a weather expert with the group WeatherWorks.

It’s back! Today, NOAA declared that #LaNina conditions have emerged for the second winter in a row. Read more at https://t.co/d6txR1BOO5 pic.twitter.com/i0l8aJTlVJ
— National Weather Service (@NWS) October 14, 2021

Forecasters said La Niña could also potentially impact the remaining weeks of hurricane season, although the Atlantic hurricane basin remains very quiet right now with no major storms brewing.

The re-emergence of La Niña is being referred to as a “double dip” by the NOAA because of its arrival in back-to-back years.

Having consecutive La Niña winters is far from uncommon. The phenomenon was present in 2016, 2017, 2020, and now, 2021, according to the NOAA.

"Our scientists have been tracking the potential development of a La Niña since this summer, and it was a factor in the above-normal hurricane season forecast, which we have seen unfold," said Mike Halpert, the center's deputy director. "La Niña also influences weather across the country during the winter, and it will influence our upcoming temperature and precipitation outlooks."
While no two La Niñas are exactly the same, they do share a few things in common.

"We've already seen one likely effect of La Niña this year—a more active Atlantic hurricane season, with nearly twice as many storms as average so far this year," associate scientist Emily Becker said in a blog post. "But the most substantial La Niña effect on North American rain, snow, and temperature happens during winter.”

La Niña is expected to last through the early spring 2022. For the upcoming winter season, which extends from December 2021 through February 2022, there is an 87 percent chance of La Niña.

NOAA will share its official winter predictions later this week, providing a final, comprehensive overview of what forecasters expect for the colder months.