When we think about unexpected and extreme weather phenomena caused by climate change, cold weather isn't often the first thing to come to mind — after all, if people have been experiencing cold weather since the dawn of time, how bad can the cold really be?
As it turns out, cold weather can have catastrophic consequences — especially when we see it in places where it is not supposed to be, at the wrong time of year, and at temperatures that are far too low to be normal. These incidents of insane and unexpected cold are called polar vortexes (also known as arctic cold fronts or polar cyclones), and they are a force to be reckoned with across the United States and the world.
The incidence of a Polar Vortex is no ordinary bought of cold, instead, a polar vortex occurs when cold air from the earth's poles makes its way into an area where it is not meant to be. Essentially, a polar vortex is a large pocket of cold low-pressure air that can be found rotating counterclockwise around the Earth's north and south poles. In the winter, when the poles are faced away from the sun, these pockets of air can expand bringing the cold air closer to the jet stream (a tunnel of fast-moving high-pressure air that moves around the earth at a latitude between 50° and 60° north and south). While these pockets of air usually exist as two perfect concentric circles, they can occasionally stretch and bend towards the equator, allowing the polar vortex to move into an unexpected area. This new cold air comes into warmer areas, pushing the original warm air up and away, and creating a new winter's landscape — complete with freezing wind, blizzards, and piercing temperatures.
Polar Vortexes are seen everywhere around the world, with 2023 alone boasting catastrophic polar vortexes in China, Afghanistan, Russia, the United States, and more. In the northern hemisphere, the jet stream that serves as the boundary between polar air and air of the mid-latitudes moves from west to east. Subsequently, when cold air is able to bridge this boundary it is often carried toward the northeastern portions of each continent. In the United States, this is often manifested as polar vortexes hitting the North Eastern part of the nation.
Topography also likely plays a role in bringing polar vortexes to the northeast. The lofty rocky mountains that traverse the center of the North American continent, may also contribute to creating disruptions to the jet stream — causing air east of the mountains to feel the brunt of the cold.
When it comes to Climate Change’s role in Polar Vortexes, a consensus still remains largely undecided. While some scientists believe that the severe polar vortexes of recent years are the result of natural variations, others state that the warming of the Arctic is the main culprit for the recent uptick in disruptions to the vortex. Those who are proponents of climate change as an instigator of increased Polar Vortexes state that warmer conditions lead to more energetic movements in the atmosphere that lead to a wavier jet stream. Others state warming near the equator creates a larger temperature difference between the poles and the equator also leading to a wavier jet stream.
While cold weather does not initially seem like a catastrophic threat, when extremely cold temperatures suddenly encroach on areas that are not expecting cold, populations can be severely harmed. In extreme cold, the body can draw blood away from the extremities towards inner organs to stay warm, this can lead to frostbite that can develop on the skin in as little as five minutes. Similarly, extreme cold can also cause individuals to lose heat faster than the body can regenerate it. This causes major organs to be unable to carry out their functions causing hypothermia. These issues are particularly deadly among older populations or those with poor circulation. For example, in a polar vortex event that occurred in the American Midwest in 2019, 21 people died as a result of polar vortex-related complications.
During the first weekend of February 2023, the Northeast of the United States was hit with a deadly polar vortex. Across the region, the icy wind dropped temperatures to an average low of minus 45°C (minus 50°F) with windchill. The lowest temperature in the area was recorded atop the 6,288-foot-high Mount Washington in New Hampshire at an astonishing minus 78°C (minus 108°F) with windchill — dethroning the nearly century-old record of minus 75°C (minus 103°F) set in 1934. The polar vortex caused intense damage across the region, being the cause of 18,000 power outages, and at least one death. Most frightening in these figures is the fact that the Polar Vortex event was sandwiched between two periods of warmth (with temperatures averaging 10°C (50°F) in the surrounding weeks).
While Polar Vortexes in the United States most often occur in the northeast, occasionally, the bandwidth of the polar vortex can stretch to encompass areas much further south — such as Texas. When freezing temperatures reach these parts of the country, they can have deadly effects, as populations and infrastructure are unequipped to deal with the cold.
On February 10th, 2021 the state of Texas began to experience unusual weather — with an influx of freezing rain and sleet. By February 13th, the state had issued a Winter Storm Warning. Over the course of several days, wind chill warnings and hard freeze warnings were also issued. The cold weather across the state lasted until February 20th — setting records for the longest streak of below 0°C (32°F) temperatures in the state's history. The state also experienced a record low of minus 19°C (-2°F).
The Polar Vortex brought about power outages throughout the southern united states, leaving nearly 10 million people without light or ways of heating their homes. The temperatures also led to many burst pipes, cutting populations off from water. In total around 240 deaths were linked to this Polar Vortex episode. The cold also had catastrophic consequences for wildlife. Officials estimate the death of at least 3.8 million fish along the Texas coast, as well as the injury of many other plants and animals across the region.
While Polar Vortexes are phenomena still shrouded in some mystery and confusion, the catastrophic potential of these events is undeniable. These events have been shown time and again to hit populations during periods when they are least expecting it. If nothing else, the drastic unpredictability of these events serves as an important reminder of the extreme weather challenges that are sure to come in this new era of climate change and how important forecasting data may be in keeping populations safe and informed.