There is a large area of cold air that normally circulates in the Arctic. During winter, scientists have often monitored this Polar Vortex region because of a familiar pattern; whenever it gets weak, it alters regular wind and weather patterns across lower latitudes. In this article, we discuss a recent forecast by NOAA that reveals this event to be underway again.
An overview of Earth’s Polar Vortex
High above the North Pole, there is a region with low pressure and cold air known as the Polar Vortex. Apparently, this region is formed every winter as sunlight continues to fade into the Arctic. Whenever this occurs, the regular temperature in Earth’s upper stratosphere begins to drop drastically.
This then creates a circulation of strong winds that remains contained across the Arctic. According to meteorologists, the stability of the polar vortex helps regulate winter patterns across North America, Europe, and Asia. Typically, this vortex makes cold outbreaks during winter brief and bottled up. However, what happens when this vortex becomes weak and unstable?
This problem arises from a disturbance tied to sudden stratospheric warming (SSW). This disrupts the circulation of wind inside the vortex until it begins to spill cold air. Eventually, this could cause temperature levels during winter to go below regular seasonal patterns for days, if not weeks.
NOAA warns about the Polar Vortex strike on Maine
Researchers from the National Oceanic and Atmospheric Administration (NOAA) noticed the weakening of the polar vortex on November 28, when a sudden stratospheric warming broke it apart. According to them, this is an unusual early disturbance where temperatures are already below the norm in states such as Maine. With nighttime temperatures going below zero.
Dr. Amy Butler, a research scientist with NOAA, says bigger impacts are likely to break out from this polar vortex disruption, which could last for the next week or two. Wind chills Thursday night would range from 8 degrees below in southern Maine to 25 degrees below in northern Maine. This would be unlike most cold snaps experienced during winter.
An analysis from NOAA reveals how this polar vortex disruption would sustain cooler air across affected regions. According to meteorologist Zack Hargrove, weekend temperatures could see a rebound before another bitter cold front arrives on Sunday.
How the Polar Vortex disruption spills beyond the Arctic
Generally, when the polar vortex weakens, the flow of cold air contained over time begins to sweep southward toward lower latitudes in the Northern Hemisphere. This then begins to interact with surface weather processes that could lead to events such as sudden snowstorms or wind chills at unusual temperature gradients. This bitterly cold air observed in late November is but a shadow of what is to come.
The effect of this Vortex disruption for December
Already, meteorologists have started recording early indications of a cold pattern across the United States. However, the predictions following this pattern suggest a broad and increased likelihood of cold air. Eventually, certain regions beyond Maine would begin experiencing this long range of unusually freezing temperatures.
This December, the regions most likely to experience this are along the Northeast, Midwest, and a few central states in the U.S. What this means is that states within this region will begin to see an unusual onset of winter. However, in Maine, residents have continued to witness atmospheric temperatures tilting towards sharper degrees.
While the precise effects of this disruption remain subject to change, researchers have seen the early events as an open window to study its extended influence on winter temperature. Research is also being conducted to better understand how high-altitude atmospheric disruptions drive these prolonged cold outbreaks across the country.
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