NJ Weather: Blast of arctic air will push temperatures to 20s. Can we blame the polar vortex?
So much for spring! A brief taste of wintry weather will target New Jersey later this weekend and early next week, with temperatures expected to drop into the low 20s in many parts of the state and possibly the senior teenagers in the hills of Sussex County.
Some daily record lows could be challenged, especially on Tuesday morning, based on the latest National Weather Service forecasts for Newark and Atlantic City.
Forecasters predict a low of 25 degrees at Newark Liberty International Airport on Tuesday – very close to the daily record of 23 degrees, set in 1959. They predict a low of 22 degrees at Atlantic City International Airport, which would bind the March 29 Record set in 1959.
Influence of polar vortices
Is the polar vortex responsible for our next cold snap? AccuWeather forecasters say “changes in the weather pattern and the polar vortex will direct frequent waves of cold air into the region during the remainder of March and early April.
the polar vortex is a giant stream of frigid air that normally circulates tightly in the stratosphere around the North Pole, but sometimes the circulation weakens as the stratosphere heats up.
When this happens, pockets of arctic air break away from the polar region, drift into Canada, and then into the northern United States. It could also drift to other parts of the northern hemisphere, such as Europe and Asia.
Influence of polar vortices
AccuWeather meteorologist Paul Pastelok said the polar vortex “has recently shown signs of weakening and separation as well”.
He says the jet stream – the narrow, wavy belt of strong wind currents high in the atmosphere – will undergo a big shift, plunging low in the southern United States this weekend. This will allow “at least some of that cold air” from the polar region to fall into southeastern Canada and the northeastern United States during the last days of March.
AccuWeather says the polar vortex will fluctuate in strength over the next week or two, so our region won’t have a prolonged cold spell – just occasional waves of cold air and warmer air until at the end of March and beginning of April.
Steven DiMartino, a meteorologist who leads the Weather NY NJ PA forecasting company, based in Monmouth County, said the weakening of the polar vortex is common at this time of year.
He said the weakening of the vortex is part of a slow process that began in late February due to major warming that has occurred in the stratosphere – the layer of the atmosphere that extends from about 8 to 31 miles above the Earth’s surface.
This process, commonly referred to assudden stratospheric warmingtakes place when temperatures rise rapidly around the north polar region, causing the polar vortex to weaken and split into multiple drops of frigid air.
DiMartino said the split that happened in late February caused most of the cold air to drift over Asia and Europe – and contributed to the recent Arctic outburst in Ukraine.
“We are now in the process where the polar vortex is naturally weakening from more direct sunlight as we move into spring,” DiMartino noted Thursday. “As a result, the stratosphere as a whole moderates, which reduces thermal gradients in the stratosphere, thereby reducing wind speeds at (certain) heights” in the atmosphere.
“It happens every year at this time of year,” he added.
For New Jersey, cold temperatures predicted for Sunday evening through Tuesday are only partially related to the weakening of the polar vortex, DiMartino said. He thinks other trends, such as changes in atmospheric blocking patterns and tropical weather phases, could play a bigger role.
Current Weather Radar
HTML block example
Thank you for relying on us to provide you with local weather information you can trust. Please consider supporting NJ.com with voluntary subscription.
Len Melisurgo can be reached at [email protected].